Stacking, yes. But I think it's mainly the Hero modes starting from 1 shot which makes it madness. That's just lazy and stupid factory setting rule design. Sorry. It is.
Construct the default mode starts to the playfield design. Xavier and Iceman are easier shots, so I'd say 4x each starts their mode. Rogue, Phoenix and Cyclops 3x. Storm and Beast 2x. Wolv 8x. That way they stack, but not in a hot mess of madness, and you can control the pace of the mode starts far better. And honestly, I don't mind the Magneto SJP qualifying Danger Room, if..
Dark Phoenix progression is more sensible. Starting all of the Villians is tough, if they don't stack, and by rule of qualification they never will. So the FGY/TV mode analogy makes perfect sense. That'd still be a bear to complete. And then...
If you reach Danger Room and Dark Phoenix, you qualify the ultimate Deadpool Finale as the final wizard mode maybe?
And add combos, of course. Not having combo awards in a layout with endless combo possibilities is just silliness.
The changes needed aren't really all that tough, and the game would just open up and be infinitely better. Hopefully Borg or Waison are following this thread...
PS- any XM owners who haven't changed the four ramp posts, please do so immediately. Immediately, if not sooner. Also, do the Hemi NC mod (in blue). Also, lamp covers on the Gambit jet leds are a must, believe it or not I tried a few and I liked yellow covers the best (there's so much red and blue on the playfield already). Enjoy!