Presumably, console.ctrlkey_passthru just needs to be set to "+@ABCEFGHIJKLMNPQRSTUVWYZ\]^_" instead of the current "+ACGKLNPQRTUVWXYZ_"?
"+@ABCEFGHIJKLMNPQRSTUVWYZ\]^_"
"+ACGKLNPQRTUVWXYZ_"
Ah, I see, ctrlkey_passthru is tied to the ANSI-specific key remapping, and CTRL-Q is down arrow.
Yeah, it just won't work with PETSCII. Likely best to whip up a different editor specifically for PETSCII.