If it isnt solid rubber (or a solid soft polymer), I’m guessing you wont like it. Injection molded plastic - like those plastic car ramps - will flex and wear out.
I was shopping around for boat dock bumpers and hated them all. I went with solid rubber bumpers they use in truck loading docs. Sun, salt air, and brackish water makes plastic brittle. Ten years later, those solid rubber bumpers are still looking like new.
You mentioned the indentation/edge is inside the garage door. I presume you know that’s there to keep water from washing into the garage. It’s a feature, not a bug

. It’s the ‘pocket’ for the garage door bottom seal.
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If you raise the lower surface, your garage door may not seal properly at the top and at the section hinges without having to make adjustments to the door and tracks. There’s some adjustability (as in fractions of an inch) but not a lot.
Hanging a garage door is not super complicated. Even so, I put my own in having never done that before and wished I had paid a pro to do it. There’s an art to hanging a door properly.