It kind of blows my mind that this isn't just the standard procedure when sharing a model on sites like Printables or Thingiverse. These communities encourage remixing models, yet the hoops you have to jump through to actually modify an STL are barely worth it.

The method I have used to some (limited) success is importing the mesh into Fusion, generating face groups, and then converting the mesh to a solid that I can work with. The problem is that Fusion (paid version, btw) fucks this process up with anything other than VERY basic models. Anything with threads, forget it.

I have scoured the internet and tried all sorts of solutions for this, using various free & paid software, and they basically all suck for even moderately complex models. Nobody ever does a tutorial with a model that I couldn't just re-create myself faster than converting someone else's STL to a format I can edit.

With how far the 3D printing community has come over recent years, I can't understand why anybody who has ever tried to remix an STL wouldn't just automatically upload an STP or something alongside any models they create & share. I know I do.