SAS defense would instantly become one of the best of all time AND Wemby & Bam complement pretty well offensively. Obviusly the Giannis trade would be better for SAS but I feel like he is going to the Mavs so going for Bam (and keeping Castle and some picks in the meantime) is a really good move for the Spurs.
As for the Heat, I feel like this core does not have any future (unless you can make big moves which seems unprobable) and getting Dylan Harper and valuable picks and players is the best move. Trying to fight from the play-ins every year to make a run like in 2023 is just stupid.