Where is the command line text so I can add my switches, and -nocrccheck, -no[whatever], etc.?
I noticed that the extra command-line options in the official experimental installer aren’t implemented correctly yet, so stay tuned! But to answer your question, for a particular engine like your desired “dle21”, you’ll want to put any extra command-line options that you want in a text file at “roms/daphne/dle21.daphne/dle21.commands”
If you want to manually fix it now, edit “/opt/retropie/emulators/daphne/daphne.sh” and at the end of the last line (after “-fullscreen”) add ” $params” without the quotes.
Or wait until someone here says it’s fixed and install daphne again.
I can confirm that I’ve run it with your settings, so GOOD LUCK and let me know if you’re still stuck.