Epoxy is tough, but it's still a polymer (plastic).
If you drop a 1/2" breaker bar, or a brake rotor, or something something else onto your bare concrete floor that will scratch or chip it... it WILL damage epoxy as well.
You'll notice all the guys with beautiful old floors either seldom work on cars... or else they're very careful with it. I've seen several photos of jackstands sitting on 1x12s or small squares of plywood, instead of directly on the epoxy.