Over the years I've made many, many different custom conference and schedules with your wonderful games!
My most intricate xml file is a four, 22 team super conference with 5 permanent conference opponents and rotating the others 4-4-4-4 every 4 years. This worked really well on DDCF 22. AND it works completely fine in the first access if I make the game with a 4 or 8 team playoff. But if I try to create the game with a 16 team playoff, the progress bar at the creating new league screen doesn't advance and it quickly stops and has the red font error message saying "an error has occurred".
I'm very happy that you added automatic qualifiers for the playoff to the game! This is something you should advertise as a very good change for us customizer and conference realignment nerds. A small issue is that when you try to change the status of a conference in the settings (in the league options menu), the tick box to change "Conference Championship Guaranteed Playoffs?" doesn't change even if you press save. I got around this by putting ConfWinnerAutoPlayoff="true" into the conferences to be auto qualifiers in the xml file. This made the tickbox check off correctly. But when I actually tested it out, a team finished 12th that won their conference championship game (therefore won their conference) in an auto qualifying conference and they did not go to the 8 team playoff. So this entire thing needs to be looked at.
Appreciate the work and reception to the feedback!