Possibly switch to fork of Discover as a base for the software center

No.
Discover, among other things, uses packagekit for package management which is buggy and a security vulnerability.
It should not be used an Arch/Manjaro for general package management.

(it is acceptable as a frontend for store.kde.org though)

PS.

Are you referring to pamac-cli and pamac-gtk respectively - so just pamac then?