i don't recommend doing this by hand, is it possible to add this option?
To my understanding pgAdmin is limited to communicating with PostgreSQL via a session - there is no guarantee that the two programs are even on the same machine. IOW, editing server boot configuration files seems outside of pgAdmin's charter. Administration of the contents of databases it what is targeted, not getting the server up and running in the first place. Configuration management tools cover the later.
I suppose it could wrap a UI on top of "ALTER SYSTEM"...
As of now there is no SQL-means to edit pg_hba.conf
You might need to accept that you are in the minority that those files should not be hand edited - ALTER SYSTEM provides for specialized usage but at the end of the day the desire for UI tools for those two (three: ident) files is pretty limited (at least relative to the cost to develop one).
