I actually had a similar idea to the "Hammer Flip" (which i assume "rebound" is based off of), as in if you press A after hitting the ground with the hammer, you could leap forward (instead of upward) and gain momentum.
That and hammering a spring forcing Amy to be in ball form would be good, as springs are a lot of times placed in front of slopes, so Amy can use them... that or you can just use Cobalt's Momentum Mod... or Rumai's classic if that works, then again that removes thok so i never use it casually, since thok is a casual dream.
Same reason I don't use the peelout, Alt Sonic has something like the peelout, but doesnt have the peelout run animation, and you can only move after the stars glow around you as opposed to whenever you want, like a spindash (or amy's peelout in advance 2).
I kinda exploded about ideas for Amy in the suggestions forum. I mainly kinda liked the idea of Amy having a crouch for custom1, i suppose thats already out the window for the actual game, but as a mod maybe. Anyway a Hammer Jump thats activated by crouching and pressing spin would be balanced, as it wouldn't be as mobile as Fang's bounce. Amy having a "sorta roll" by using the Big Step [Amy does a hop] (crouch + jump) and then pressing spin during that would make Amy fall on her face and have a semi-roll thing... i mean it pulls from her first playable appearance in a 2D game.
I'm not asking for this in here, as that'd be a SUPER big change, but maybe the spin when hammering a spring may be good enough, as that allows Amy to use a lot more slopes than she previously could in vanilla srb2. Also makes it so some mods that want to use slopes can have a spring there, Or a mod that ALREADY has a spring before a slope, will make the level more doable with Amy.
I like the idea of a nerfed hammer jump, to where its more situational, instead of Amy having super good mobility, and skipping most jumps with it. She can move after performing the move, but she has to come to a complete stop, making it less like Fang's gameplay. And just more balanced in general. Maybe it'd be as good as Amy with the Whirlwind jump, I don't want you to give the player too much height.
[Random Amy Ideas]