I kinda wish I went with Time’s Pulse on DuoLyon over Joint Drive Atk as it would make Galeforce a lot more consistent than the QP seal he is currently running. I went with the 300SP for arena scoring, but I think it really didn’t matter.
I run the same Stance on my FLyon and the QR seal, but I did gave him Pulse Smoke like you suggested. I have to say though, I don’t really like it. He doesn’t really have a player phase to reliably activate it, and on EP he tends to bait from afar, so the smoke doesn’t trigger on anyone. I think a C skill that allows him to secure more kills on the first hit is what I’m looking for. Something like Joint Drive Attack or Time’s Pulse with an offensive special (Glimmer or Ruptured Sky), so he can ditch the QR seal and go with Sturdy Stance instead. But those skills are pretty hard to get, so Pulse Smoke is what he is currently using.
OG Lyon’s build is pretty amazing too. I never considered NFU for him, but his spd is kinda servicable, so it looks like a really interesting choice.
Regarding YLyon, I did get pittybroken by a Marianne when going for him, so the Duel feels kinda appealing. Too bad I don’t have a source of Duel 3 so he can also get the Drive Res.