Well the timeouts and crashes were when I tried to render without strip rendering. So it was 20k x 5k of a very heavy scene.
Usual cryptic backburner errors, essentially it wouldnt render.
Even if I untick ‘adjust resolution’ it still seems to only do one eye.
Ok. You could generally turn off the “Get resolution from MAX” option and keep the 3ds Max resolution to something small like 320x240, and use the V-Ray VFB only. This should save some memory, but you’ll have to use the V-Ray VFB output options. See for example this topic: Chaos Docs