I agree, multiple iterations result in lose of information, however in many cases, even if that happens it is still faster to get partly correct mapped data, otherwise everthing must be painted from the start anyway. In my case, up until now I had to regenerate and paint groups, radius, weight from the start every time, but it's way faster to fix 1-10 vertices, instead of painting from scratch. Yes, I could try workflow with textures, but as you said, not everything can be done and it requires additional setup and skills.
However, the problem is that current workflow is completely destructive - I understand problems with the case above (where number of triangles is different), but in case where mesh is exactly the same, with exception of positions of vertices it could be done better, because user data does not change overall, I want to keep groups, weights and all the stuff, there is no data lose, I just need to auto update constraints, and that is all. So it would be great if there was non destructive regeneration in any form.
However, the problem is that current workflow is completely destructive - I understand problems with the case above (where number of triangles is different), but in case where mesh is exactly the same, with exception of positions of vertices it could be done better, because user data does not change overall, I want to keep groups, weights and all the stuff, there is no data lose, I just need to auto update constraints, and that is all. So it would be great if there was non destructive regeneration in any form.