The topic of CSPA and aging out always confuses me way more than it should. I can't imagine how some of you non-native English speakers manage to get through all these forms and roadblocks.
See my other recent topic if this helps your calculation (https://www.visajourney.com/forums/topic/790922-can-someone-check-my-cspa-math/). I'm no expert, but if your DS-260 was applied and processed as F2A(F22) and DQ'd, I think the children are locked in and aging out is not a concern anymore. Its the period between I-130 and DS-260 where aging out can be a factor because the DS-260 will be processed in its own visa class lane whether the applicant be spouse, child, married, petitioned by USC or LPR, and age is one of the factors to specify the class (I think).
At any rate, yes, 1 of the children did cross over 21 when the I-130 was in process (the other was still under), and the whole time until now all correspondence is processing as they are under 21. And these aren't my children, I'm just trying to help my LPR in-law with her children.