Hello, I have the same question as this guy
https://gamefaqs.gamespot.com/boards/375087-pokemon-crystal-version/76556607
In order to get a 100%, I need to rematch these trainers at their strongest teams, but I don't know how can I force them to call me for a rematch.
I searched for ar codes, but found none, as well as event flags in pkhex, but I only see flags to make them already battled, and not waiting for a battle/rematch.
Any solutions would be appreciated.