Thank you Dorin! I know GridConstraints in Java are very tricky. It is much better, unfortunately still not correct (perfect). I show the screens in Flatlaf, but in Metal it's the same.
1. The window after maximizing comes back. Well done!
2. But both after maximizing and in the starting size, the splits are minimally too small. Edge List Frame shows the scrollbar at the bottom, so it's still a bit too narrow. It's ok with the slider, but there are languages where the words are very long, for example German ;-) That's why it could be slightly wider.
Couldn't the width be programmed relatively? 60% 3D View, 20% Edges, 20% Slider?
If this is not possible or is too expensive, then maybe enough rising the insets?
