No Picker at all on MacMini late 2012 w/ PC keyboard?

I think I've followed instructions correctly but need help.

Victim is a MacMini Late 2012 (Macmini6,1) with Catalina now.

Have USB created, have installed OpenCore to drive, everything went perfectly fine but no matter what keys I try to hold down at reboot (Opt aka Alt, Esc, Space) no Picker ever appears. 1000 tries. No matter what I do boot goes:

Shutdown -> Blackscreen -> Chime -> Apple logo progress bar -> Catalina Finder / Desktop

One suspicion - computer uses a wireless Logitech Mouse & PC keyboard - could that be the problem? They have always worked flawlessly but maybe they are not supported during hardware boot?

Can I force the picker to show all the time with some other hackery without the key press? Do I need to dig up an old Mac bluetooth keyboard or hardwire USB keyboard or something? Thanks in advance.