I'm surprised to see this posted... I have to deal with it constantly in North Carolina I was hoping the rest of the world was pretty much free of it.
Here, there is a belief amongst the Christian worship community that 432 is spiritually more holy or something like that.. as a result, I see a lot of train wrecks.. students come in to practice in 4:32 and it takes us a minute or two to figure out why everything's wonky with their tuner, or when I'm producing and recording, I've learned to start recession with is everybody on the same tuning standard?
As far as the actual timber, I think there's just too many variables to count. In classical orchestras, there were many experiments before 440 was standardized and it is true that you will get slightly different resonance in different instruments at different standards.
However just because the violin feels they're warmer down a couple of cents doesn't mean that the trombone isn't now a little muddier if you get my thinking...
Honestly, I think this is one of those Just Play Your Guitar moments where you can overthink anything... but in this case easily trainwreck a performance.