In our project (about ~2000 plugins and features) we have very large and deep inheritance hierarchies. When opening the quick type hierarchy view (ctrl+t) on some methods, it takes a very long time to open the view and Eclipse ui freezes while the view is being opened.

See this sample of opening a method in our project, about 120s to render the view on 4.38.0.v20251020-1800 on a windows machine:

This issue boils down to the fact that the view expands an extremely large inheritance tree (about 17000 classes) when opening.
The fix from #1954 for related issue #1830 does not apply to this situation because there are no duplicate subtrees involved.