440 and 432 are both divisible by 8hz (a Schumann frequency)
the "key" is whether the key you are in, is evenly divisible by 8hz, which 440hz is not.
AND
It's only 432hz for instruments tuned to A4
ie- If the base tuning is in C0, the frequency would be 16.05hz, vs the 16.35hz it is for the ISO standard.
So tuning an A440 instrument to 432hz is more accurate, if you are looking to harmonize with the Schumann frequencies.
That is all.