There is a cmd line option but in my testing it made no difference. That is, starting with -G 10 still didn't behave as if gap limit is 10 and see new addresses used.

If this would work it would probably be good enough as users could simply alter the menu/icon start cmd to have this option set.

However, I did find that if your add a 'gap_limit': 10 at top level in the wallet file then it does behave correctly and respect new addresses. ie. red addresses become normal.