Well like a dumba$$ I went and got P3Dv4. Been very, very slowly testing my main "go-to's", the AS Beaver X being one of them.
It's working here; using the replacement cab and stock paints. Sometimes I have to flush the shader cache more than once to get an aircraft to work. I'd suggest flushing the cache and letting it rebuild. I also suggest no autogen vegetation (huge frame-rate hit) and try textures @ 2048x2048. x64 sim platforms "like" higher texture resolution.
From what I've seen so far, this version has the potential to run very, very smoothly literally right out of the box. Mind you, I'm using my old testing system:
EVGA 680i sli
Core 2 Duo X6800 o/c @ 3.809
8gb DDR800
W7 x64 ULT original release candidate rolled up to May 2017.
I'm currently running v4 box stock, no addons to aid in troubleshooting. I have swapped in a GTX 1050 ti card I use as a dedicated Physx card because it's got 4gb vram.
plug_nickel