I have an issue with Renoise 3.2 HiDPI/Retina mode on macOS 10.14.6 on my 2018 MBP 15" (base model):
When I use the HiDPI/Retina mode with 200% scaling, the UI scopes updates are slow as if the framerate is at 15fps
Alternatively, when I right click on the Renoise.app and check the “Open in low-resolution” checkbox the performance of the scopes is normal (but I can’t use the display scaling anymore)
I hope you can look into this, as I would like to use the display scaling. Let me know if you need additional information.