I did have 2 of the ones I was holding change another part of the return, when the UCE was applied.  The retirement savings credit is tied to AGI Not MAGI.  So the UCE lowered them down to a point where an IRA could save them an extra $200 or so on their return.  Most other calculations are based on MAGA not AGI so are not affected.  Or was MAGA another time or dream gone by.