Here's a summary of NSC/ROM chip locations - and which drivers work:

"CD" ROM socket: C000-DFFF (internal) ROM space - all drivers work
"EF" ROM socket: E000-FFFF ROM space            - none I've seen yet
"CF" ROM socket: C000-FFFF (internal) ROM space - all drivers work
Slot ROM socket: Cs00-CsFF (slot) ROM space     - NS.CLOCK.SYSTEM works

And here are the drivers - and ROM pages they check

ProDOS "SWU.SYSTEM"      - internal C3
ProDOS "NS.CLOCK.SYSTEM" - internal C3 C8 / external C1-C7
GEOS   "NoSlot Clock"    - internal    C8