Worked like a charm. The only risk is that I run something in the openhab-config tool which is newer then the installed package version of openhab and it breaks it. But frontail for at least and probably also other tools can be installed with this method without having to worry about installation & setup
openHABian is a set of tools that includes the same openHAB package and using the same method as the one you’ve installed. There shouldn’t be anything specific to the openHAB package inside openHABian to conflict with what you already have.