Am I allowed to sell 3d models with the .blend extension on TurboSquid

I used to sell with .obj, .max, .fbx, 3ds extensions but am I allowed to sell some in the .blend format?

am I allowed to sell some in the .blend format?
Yes you are

Yeah, since Blender is growing, that will help people get to know it somehow.

I believe the vast majority of Turbosquid shoppers (after twelve years) still use Max, Maya, and the other commercial apps, so you’re limiting your audience a bit unless you can also provide the file in another format such as .fbx.

As much as people like to say that Blender is growing, the marketshare is still rather tiny like it is with every other FOSS application in the creative space.

Have they got the FBX export pipeline fixed now?

I’d agree that .blend is fine as long as it meets all the other rules. And there will be some market as Blender adds no extra cost to use and people can always convert with it. However I think you’ll find the biggest market is .obj as it’s the most ubiquitous and broadly supported across 3D apps. Perhaps followed by FBX if it’s something that’s rigged and ready for use in a game engine or animation.