In this part of the manual:
It is explained how to set up key commands for your (custom) project logical editor presets.
I was very surprised that when trying to same procedure for the MIDI Logical Editor, it didn’t work. I.e. my custom presets didn’t appear under “Process Logical Editor” folder, which contains all the factory presets. I wonder if this is a bug. If it is - I’d like to report it. If it’s not - I’d like to simply feature request this. (I expect the behavior in this to be the same as the project logical editor.
UPDATE:
I have found a workaround for this. (At least for windows) Apparently your custom files are saved at
C:\Users\<youruser>\AppData\Roaming\Steinberg\Cubase 10.5_64\Presets\Logical Edit
All you need to do is to copy them to the folder specified in the manual:
The Project Logical Editor presets are stored within the application folder in the Presets\Logical Edit Project subfolder. While these files cannot be edited manually, you can reorganize them (e. g. putting them in subfolders) like any files.
And this solves this issue.