I know something like this has been mentioned in the past, but all those messages are years old, so I’m starting a more current post.
From what I understand the default for claiming the donations is on the higher income earner return, but that isn’t always the best approach.
I have a situation where the husband has the highest income and a refund. The wife has a balance owing due to have some rental income, but if I can get the $2,000 of the $2,200 donation onto her return and $200 on his return this means no one owes any money and they get the best result.
I have to turn off the optimization and override everything to make it all work. It would ideal if took the balance owing from the lower earner into consideration when deciding what the optimal situation is.
I’ve had to do this kind of manual adjustment on 3 couples out of the 100 or so returns that I did this year.
Something to consider for next year I guess.