Yeah there is a migration guide one www.vreue4.com for changes that have to be done to projects to go from .25 to .26.
I ported VRE to chaos when it was default in early previews of 4.26, but chaos was far too unstable and broken to be useable (which is why they reverted it being default and made physx default again for now). And no, chaos is not at all currently feature complete with physx.
VRE will still run on chaos currently, I didn’t strip out the chaos pathway code, the only major caveat is that the vehicle class is not cross compatible due to how they changed things so it has to be changed between chaos and physx.
I “may” release a chaos specific branch with the chaos vehicle class if the chaos default version of 4.26 is actually stable enough to care about. Last impressions of it were that it needs months of iteration more, literally could not test features on it due to crashes, performance issues, and lack of actual 1:1 with physx, meaning that I don’t know if the current force units of measure are actually going to remain or be changed.
Edit As negative as that sounded regarding chaos, it is only because chaos was attempted to be pushed far too early. I’m sure that after enough development time they will iron out these issues, and the upsides to chaos with its additional feature set and better framework are huge, I very much look forward to it being stable.