As vr user, moving more workload to the GPU is a good thing, it's not that their isn't a cpu impact, but anything that reduces cpu load is a good thing.
Also cloud effects, and reflections in water and clouds, cockpit lighting effects etc...
From memory, shadows specifically have a high CPU impact, as do mirrors for example using ray tracing would enable those functions ( abd others) to be offset to the GPU, which would improve performance on those GPU's capable of ray tracing...
its pretty normal ... the MR/ASW basically is guessing what the next frame will be sometimes it gets it wrong... the more CPU and GPU overhead you have the less bad the guess is
I suspect the issue is that the MT isn’t quite ready yet, and it needs some help on some processors to optimise its use… physical processors start at 0 and then every other processor is virtual , so 0 2 4 etc… are physical when dcs is running set the processor affinity to those even numbered processors… good luck !
You should try this first
No you still need wmr and Openxr for windows... But you don't need steam
https://learn.microsoft.com/en-us/windows/mixed-reality/develop/native/openxr-getting-started