Dont know is it just a beta but importing .usdc from Blender 2.82 is tiny inside Unreal but fbx is excatly 1:1 size like it should be. Do not tell to make Blender viewport scale 0.01 as it messes up my senses when building in normal metric scale. I just hope it is just a beta quirk and in future all conversions are done automatically in background. Fbx is ok as always for normal mesh exporting and sizes are all 1:1 like it should be except known animation problems and hacks that are needed.
Tested usd export out of interest, nothing more.