Sorry for the massive post. If you need to see a bigger pic, right click and copy the image address and then paste into your browser address bar. Thanks to antic604 for mentioning the low resolution option and the tutorial here: https://imgur.com/a/0P5KY
1. Copy the Bitwig Studio.app and paste it to a new file in your /Applications directory.
2. Rename the copied app to something like Bitwig Studio LR (for low res) so that you can run Bitwig in either low or high resolution.
3. Copy the Bitwig Studio LR.app from the /Applications directory to your desktop.
4. Delete (Move to Trash) Bitwig Studio LR.app from the /Applications directory
5. Right click the Bitwig Studio LR.app on the desktop and select Get Info.
6. Open in Low Resolution in the info window should show unselected and greyed out.
7. Right click on the desktop Bitwig Studio LR.app and select Show Package Contents.
8. Double click on the Contents folder in the Finder.
9. Right click on Info.plist and select Open With > TextEdit.app
10. In the TextEdit editor locate the NSHighResolutionCapable key and modify its string value to "NO" in all caps and without the quotes. Save Info.plist and close the TextEdit editor.
11. Copy the desktop Bitwig Studio LR.app back into your /Applications directory.
12. Right click on the /Applications directory Bitwig Studio LR.app and select Get Info. The info view should now show Open in Low Resolution greyed out and selected.
13. Right click Bitwig Studio LR.app in your /Applications directory and select Show Package Contents.
14. Double click Contents in the resulting Finder view.
15. Right click on Info.plist, and select Open WIth > TextEdit.app
16. Modify the NSHighResolutionCapable key string value to "YES" without the quotes and in capital letters. Save the file and close TextEdit.
17. Right click Bitwig Studio LR.app in your /Applications directory and select Get Info.
18. The Info view should still show Open in Low Resolution greyed out and selected.
You can now open Bitwig Studio LR.app and it should open in Low Resolution mode. The GUI should perform better. You can run in High Resolution by opening your original Bitwig Studio.app.
What I imagine is happening here is that by removing the Bitwig app from your applications directory you are clearing out plist and other app settings (if you have app cleaner). Making the change on the desktop does not apply the settings specified in the Info.plist to the application until you move it over to the Applications directory. When you do that I would guess OS X uses that plist file to generate a launchable application within their framework with all of the specific settings and parameters specified in the plist. I think Bitwig must be relying on the high resolution parameter in the plist when launching, and by changing it after the application has already been initialized by the OS, we're able to tell OS X to try launching Bitwig in low res mode while still passing the proper value for the NSHighResolutionCapable to Bitwig. I'd guess Bitwig is expecting that value to be set to YES and then is configured to automatically determine the proper resolution when the application launches based on system settings and params received from the OS.
These are some pictures of the differences. I'm running on 2560x1440 right now, but on my 5k iMac at home, the difference was only slightly more noticeable.
Low Res:
High Res:
