This is intended to be the last beta, if everything checks out I'm uploading it as mdledit v1.1.0. This version has a completely redone vertex normal and tangent space vector calculation algorithm, which also affects smoothing group calculations. Generally, mdledit will calculate the intra-mesh normals correctly, it will calculate those inter-mesh normals where only two vertices overlap correctly, but where more vertices overlap, it's more likely to fail. I can't spend more time on figuring out how to calculate those right now, but there will probably be improvements in the future, just like this was an improvement now. When compiling models there should be no issues however, inter-mesh smoothing really does work now. Some crash issues are also fixed, one that I found myself and one that DP encountered with the K1 endgame area models.
mdledit_v1.0.9b.zip
mdledit_v1.0.9b_xp.zip