[hjek]

> Even on a pretty powerful system, having a project timeline longer than an hour made the entire interface run at ~5fps for me when adjusting cuts.

Did you use proxy clips? It's not on by default[0].

[0]: https://userbase.kde.org/Kdenlive/Manual/Projects_and_Files/...

[Inityx]

I did not, but the source footage I was editing was 720p 30fps so I don't think that would have been much help