Every single Cubase version has its own Preferences folder. Cubase Preferences folders are:
Mac: ~/Library/Preferences/Cubase X
Win: %appData% Steinberg/Cubase _X__64
So in your case, you would see:
- Cubase 10.5_64
- Cubase 10_64
- Cubase 9.5_64
If you delete just Cubase 10.5 preferences folder, the other folders remain untouched. So once you start Cubase 10.5 (for the first time after deleting the preferences), Cubase 10 preferences will be inherited. There is a mechanism to inherit an older Cubase preferences to the new one. Cubase tries to inherit the preferences back up to 2 major versions. That means to Cubase 10.5 the preferences of Cubase 10, 9.5, 9 and 8.5 would be inherited. If you would have only Cubase 7 preferences in your folder, this wouldn’t be inherited to Cubase 10.5.
Yes, you can copy and rename your Cubase 9.5 preferences folder to Cubase 10.5. But if you don’t have Cubase 10 preferences, you don’t have to do this. Cubase 9.5 preferences would be inherited to Cubase 10.5 automatically after the very first Cubase 10.5 start.
This inherit feature might be sometimes also tricky. Imagine you have an issue in your Cubase 10.5 preferences, but the issue might sits in Cubase 10 preferences already. You trash your Cubase 10.5 preferences folder, start Cubase 10.5 and the issue remains. I always recommend to ZIP all preferences folder (as a backup) and delete them all in these cases. Then you are sure, Cubase starts with factory settings (preferences).