As a retired field engineer for a major manufacturer, who recommended using "self-leveling concrete floor". An uneven floor can present real problems getting the bottom breakers to rack in. Specifically, the cell isn't square, the center is higher in some places, which causes problems getting the secondary disconnects to mate and the ground bus to connect. One customer who was having these problems wondered why they didn't recommend setting the cabinets on embedded channels with spacing similar to the shipping channels. GE MagnaBlast breaker cubicles were always set on channels.

When using self-leveling concrete flooring you have to have tolerance of less than an 1/8 inch between several cells to have everything inserted smoothly.

I haven't seen many concrete or steel coatings that will stand up to steel circuit breaker wheels, supporting several hundred to 3400-pound breakers very long.

Sort of in the same line. We use pre-fabed buildings with switchgear, and the floors where the wheel from the trucks will wear out the paint. But the steel floors seem flat when new.
That said, in the buildings we use the switchgear is made by the same manufacturer as the building.
So, maybe ask the gear manufacturer what they recommend.