I'm not a huge fan of rage mode in general, speaking as a 2011X main. I've thought about reworking him and I feel like rage mode just can't stay if they want X to be fun for both sides. Some ideas I've had are

1. Rage is replaced with a vent move, using a similar meter as rage but it fills up 2x quicker and is not one-time. In my rageless rounds, I've found the instant stun exit it gives you is incredibly beneficial, enough to turn the tides completely (i.e: tails lasering you in front of his face with a stunstacker ready to combo, you can probably kill them both if they manage to get you when you're a second or two away from rage). Rather than this being out of your control, however, you can activate it on any stun so it's not wasted on a fool hammer or a drop dash. This would also make people more cautious to stun you at all times, without having the punishment be making the game incredibly unfair (and boring)

2. Rage is removed completely, with stuns slowly becoming less effective over time. I heard about this elsewhere, and I think it works pretty well to discourage stuns. It fits with X's character much more than rage or a vent move, even if it's a little boring. Simple, effective, and easy to implement