Humm to be honest I haven’t digged yet into physics, but basing the whole physics system on a proprietary GPU system doesn’t make sense to me. That would leave everyone with AMD GPU with no physics.
On the other end you can always make your own determinism physic engine for the logic model while having physix make your graphical model looks great while having a kind of “spring” feature that always bring the graphical model as close as possible with the logic one.