I don’t remember what specifically the OWC .pdf said, but if you search their website for the Envoy Pro FX SDD Setup instructions, it answer your questions.
I saved the setup install files elsewhere, then reformat the drive as standard/regular apfs (not any of the other apfs options).
Seems okay so far, but I haven’t run any speed tests yet.
I figured that if I have any problems, I could always go back to the setup files if I need to, but I don’t expect I’ll need to do so.