A lot of the information you’re looking for is available in the GPU metrics table that amdgpu already fetches from the hardware.
However there aren’t “sensor sysfs files” to represent every single one, just the ones that are most interesting.
If you would like to export more information available to to userspace you can write a patch to introduce additional sensors sysfs files to amdgpu that pull more information from the metrics table.
All existing sensor applications would pick them up directly then.