Crashing for me too.
Downloaded and installed the latest RadeonProRenderForBlender_3.0.8_MacOS.zip for blender. Crashes upon activation of the add-on.
MacBook Pro 2015, Mojave, Blender 2.91.0
don't worry- this also happens with blender 2.9 all the time. It crashes my imac (retina, 27inch 2017) EVERY TIME so badly I cannot even get any log data because the computer just refuses to react and fades to black. I guess this software simply is not made for the use with blender and/or with apple computers. It even crashes the program if I turn on the Pro Renderer at the start of blender with the default cube with no settings at all!!!