Thanks to everyone who has been contributing feedback! We won’t all agree on the same priorities, but I’ve already been able to make some improvements based on your contributions.
My goal here is to create a (relatively) brief reference to help newer players make purchasing and placement decisions for utility CEs. Tier ratings are, of course, my own, and mileage may vary depending on what each player prioritizes. I’ll provide some context for my ratings in the write-ups.
The following CEs are, for the most part, purchased with Mana Prisms, though Rare Prisms may be required to unlock them in the MP shop if one has missed their initial run.
Edit: I won’t be talking about event CEs in the RP shop, like Fondant. This particular list is only for CEs with utility like bond gain, QP gain, and so on.
All effects are listed at Max Limit Break (for those that aren’t automatically MLB)! Please never put these CEs on your support list if they are NOT MLB.
[S TIER]
CHALDEA TEATIME (CTT) 
Effects: +15% Bond Points earned when borrowed/+5% Bond Points earned when owned
Why: this is the CE to borrow from friend support when you do not need to borrow a CE with starting charge or other bonuses. Although the bonus is less for the copy the player owns, the community as a whole depends on other players having this up on their support lists. Not having this CE and/or placing it strangely will likely result in reduced FP income.
Support List Placement: you can’t go wrong matching this with the supports who are in high demand, namely Castoria. For Castoria in particular, I highly recommend putting her in Caster because most players expect to see support Casters with CTT there and may overlook yours if you put her in All. On the other hand, All is a convenient spot for non-system CTT picks like Douman, especially since it’s the very first icon from the left and will be chosen frequently by players who prioritize these Servants.
CHALDEA LUNCHTIME (CLT) 
Effect: +10% Bond Points earned (same whether borrowed or owned)
Why: this is the best CE you can equip for yourself for bond gain, and it’s a reasonable backup choice on support (although no one will choose it if they have their pick of the same Servant with CTT instead, so don’t bother putting this on, say, Castoria).
Support List Placement: as mentioned above, don’t put it on currently popular support Servants, because no one will choose it. It’s mainly for use in your own party these days, but you can place it where you would have liked to spare a CTT but can’t or won’t. E.g., if your friends want Castoria, Merlin, and Douman with CTT, but you want to keep Skadi available in case someone needs her, you might at least put this on her so that they get most of the bond benefit if they choose to borrow her.
[A TIER]
HEROIC SPIRIT PORTRAIT 
Effect: +50 Bond Points earned (this bonus is flat, is not percentage-based, and cannot be further modified)
Why: 50 BPs doesn’t sound like that much, but it’s better than 5% for all currently available Free Quests and most quests in general, and the party cost is low. If you can spare the RPs, it’s worth getting if you will consistently slot it. Note that this CE is MLB’ed upon purchase.
Support List Placement: generally, don’t. No one will borrow this over CTT unless perhaps they are running a very low-level quest repeatedly, in which case they will probably borrow the similar CE for flat Friend Point gain.
GREAT DETECTIVE FOUMES (Foumes) 
Effects: +5% Bond Points earned/+5% QP earned
Why: this CE offers the two useful effects with a pure ATK bonus (up to 2k at lvl 100), making it a mainstay for bond farming teams and for QP farm.
Support List Placement: this CE is unlikely to get you any significant amount of FPs; I admit that I’ve never borrowed it, myself. There’s no reason to borrow it when CTT is out there, and if you want to focus on QP farming, you’re looking for a different CE on this list…
BELLA LISA (BL) 
Effect: +15% QP earned when borrowed/+5% QP earned when owned
Why: although QP farming becomes less of a priority if one engages with lottery and raid events, there will almost certainly be times (especially as a newer player) when one wants to hit the QP dailies, and this is what you need to borrow for maximum benefit.
Support List Placement: most players expect to see this in the Rider slot for a couple of reasons. 1) the QP dailies are always Caster enemies, and the game by default shows you the Rider list; 2) the Caster slot is more likely to have CTT except sometimes during 1/2 AP dailies. Now that we have triple support lists, making a copy available in Caster isn’t a terrible idea, but I would avoid putting it on Castoria unless you know for a fact that your friends depend on this for their QP farming, because many players outright ignore those dailies and want only CTT Castoria.
MONA LISA (ML) 
Effect: +10% QP earned (whether borrowed or owned)
Why: same relationship to Bella Lisa as Chaldea Lunchtime has to Chaldea Teatime. This is the copy you most want to prioritize in your own party, though of course you can and should field both this and BL if you want to maximize QP gains from a quest.
Support List Placement: this CE is not a priority for support lists. No one will borrow it when BL is on offer, and bond gain CEs like CTT are in much higher demand, anyway.
[B TIER]
GRAN CAVALLO 
Effects: +5% Bond Points earned/+5% Mystic Code XP earned
Why: because +5% bond and because Mystic Code XP is nice to have if you are actively working on a doozy like Arctic. With this CE, you can have your tiny cake and eat it, too.
Support List Placement: irrelevant, because no one will borrow it.
CHALDEA DINNERTIME (CDT) 
Effects: +5% Bond Points earned/+5% Master XP earned
Why: it’s one of several +5% bond CEs and thus has a place in most bond farming parties. The Master XP portion is fairly irrelevant, though technically it offers some benefit whenever the Master Level cap is raised, like it was recently.
Support List Placement: no one will borrow it.
[C TIER]
TAKE ROMANCE 
Effects: +5% QP earned/+5% Master XP earned
Why: it fits into QP farming parties because of its +5% bonus. The Master XP bonus isn’t very important. However, you might prefer to prioritize some bond gain, especially Chaldea Lunchtime, over an extra 5% QP.
Support List Placement: no.
FREE SEATING 
Effects: +5% QP earned/+5% Mystic Code XP earned
Why: as with Take Romance, this is one of the options for further boosting QP gain when needed. Just like Take Romance, however, you might want to swap it out for something that offers a greater bonus to bond or another resource you prioritize.
Support List Placement: no.
[Honorable Mention]
BEGINNING OF THE JOURNEY (BotJ) 
Effect: +75 Friend Points from using Friend Support (automatically MLB)
Why: after some discussion, I’ve decided to give this CE its own listing. I do not use this CE or recommend that most players do so, but a player less focused on bond gains and looking either for something to fill a gap in party cost or for a way to supplement their FP income so that they can roll the Friend Summon for more Servant Coins they can use for creating Holy Grails (future update) might be interested. I would stress that this is a niche pick and shouldn’t be considered until after higher-priority CEs have been acquired.
Support List Placement: I wouldn’t, but if you have friends who are on the same page with you and don’t care as much about bond, you can help each other out.
[THE D LIST]
EVERYTHING ELSE (Friend Points earned, Mystic Code XP earned, Master XP earned, various combinations thereof)
Why: all of these are extremely niche. Worse, they compete for slots with bond gain CEs, of which there are many.
Friend Points - unless you are playing in a very specific way and to the exclusion of arguably more important priorities, this is not a useful area to prioritize.
Mystic Code XP - you will eventually reach a point where all of your Mystic Codes are leveled with long stretches between new MCs. MC XP takes care of itself and doesn’t need to be rushed at the expense of bond.
Master XP - it’s worthless. Just playing the game will level you up just fine.
” has been incredibly freeing. Though I did my heavy mc leveling before bond 10+ was a thing and was on track to waste bond exp if i rushed bond too aggressively, but I still highly value not needing to balance which mc needs leveling vs which mc would suit the team best despite how much mc exp has been wasted in ~18 months since completing my mc’s.
I use BotJ in almost every comp thanks to it’s low cost. FP is way more valuable now than it used to be, so I think it’s taken a greater importance.