Nice model!
I can try to make the process smooth.
BTW, did you double check that your Meshlab version is up to date?
I would really avoid situations where "once you pass [a given] point, there's no going back": it should be possible to avoid that. Also, MeshLab is not supposed to be crashy or picky, even if sometimes it is, so maybe it can be fixed too, if the error is on its side (I'm among its developers after all). For sure, MeshLab adopts an internal structure for meshes which is quite different than M&B one, especially in terms of storing attributes (normals, UV, colors...). It is way more general, but also fall shorts in some respect with respect to BRF. This make some algorithm a lot more complicated, some other a lot simpler.
Right now I'm extra busy with RL, but I'll be able to have a closer look at these problems (hopefully) soon.
Maybe someone PMs me a brf that is problematic, with simple instructions, like: "export it as ply, then import in mehslab, and it crashes/it destroys UV".