I don't use Blender 2.9 or above because I use Sims4Studio and Sims4Studio does not support the higher versions of Blender. I use Blender 2.78. When it comes to TSRWorkshop, I always export and import meshes either as .wso or .obj. depending on whether I'm making a TS3 item or a TS4 item. If it's a TS3 item I'm making I'll export the meshes as .wso and import them into Milkshape to assign joints then export as a .wso again. If it's a TS4 item I'm making and I'm using TSRWorkshop, I'll export a mesh as .obj and import the .obj into Blender, do what I need to do, then export as .obj again. Honestly, If you're making TS4 stuff use Sims4Studio. It works directly with .blend files and is a heck of a lot more stable than TSRW. TSRW crashes constantly and it takes forever to load the game's catalog. The only issue with Sims4Studio is that it doesn't support any versions of Blender 2.8 and above.
