You can designate either home as your primary and the other home as your secondary for 2023. But there is no reason to treat home A as your primary because home A will clearly be a rental going into 2024 making home B your primary by default. It doesn't matter how the homes are designated or which one has more interest as far as deductions go. It all gets added together.
You can also treat home A as your secondary home for all of 2023 and treat it as a rental beginning in 2024.
I suggested making home B primary because if points are reported on the 1098, you can deduct all of them on this return instead of spreading them out. (Note: technically you have to had paid out of pocket for any reason into escrow in an amount equal to of greater than the points charged but Turbo Tax ignores this.) If you did designate home B as your secondary, you can still deduct interest for home B but points must be spread out over the life of the loan.
