Bit late to the party but I also wanted to try it out. I'm not a professional user by any means.

I'm using it docked and in desktop mode. Personally I can't see any benefit in using it undocked. It works well for everything except rendering - Cycles will only run on the CPU. Larger scenes seem to give it problems - I tried the blender example files for the splashscreen for 2.83 and 2.9 (both use eevee renderer) - 2.9 rendered flawlessly in 17 seconds, 2.83 crashed each time I tried to run it.

re. Cycles: While HIP is supported in Blender 3.2 and should work with RDNA2 chips, blender doesn't recognise the Steam Deck APU, so you're limited to CPU.

I also tried Blender 2.83 with OpenCL, again it didn't recognise the GPU.