Ive gotten double 5* exclusive a few times in the past. Back in 2019
I don’t know about it being wrong in theory, but if you wanted all four different units more than you wanted as many 5*s as you could get for your orbs then I think yes it’s better to stop pulling a colour when you get the focus unit of that colour. Because if you don’t, you’re firing orbs at a unit you already have instead of firing the same orbs at a unit you don’t have.
Yeah i will try that next time i want for a red