Performance/ lag issues in v2.5.1 (1141)

I’ve been experiencing particularly slow performance for some time. I think this started a couple of versions ago, but either way is occurring with v2.5.1 (1141) as well as the beta v2.5.2 (1150). Framerate while scrolling is particularly low in the Font overview tab, even with a small character set (16 glyphs).

I’m running macOS 10.14b, but the issue was also present in 10.13 stable.

I’ve tried launching without plugins, but they don’t seem to be the bottleneck. Macro console shows no errors, and I’m not writing more than a couple of words in the edit view. Is there any information I can provide which might help diagnose the problem?