After some intense experimentations, I have a few terminal shortcut configurations I like. This one is used for documents:
gsettings set sm.puri.phosh.osk.Terminal shortcuts "['Cut', 'Copy', 'Paste', 'Undo', 'Redo']"
This one is an application launcher based on the prior post I made above:
gsettings set sm.puri.phosh.osk.Terminal shortcuts "['WWW', 'Mail', 'Calculator', 'Explorer']"
If you want to combine them, along with “Tools” to split the shortcuts into two distinct sections:
gsettings set sm.puri.phosh.osk.Terminal shortcuts "['Cut', 'Copy', 'Paste', 'Undo', 'Redo', 'WWW', 'Mail', 'Calculator', 'Explorer', 'Tools']"
Currently, Shift, Alt, and Control cannot be created as standalone terminal shortcuts, as I suspect it has to do with them normally being toggle buttons.