A) Use the sort of skates that can deal with the surface. My case, that's the tall urethane-roller ones, similar to pallet-jack roller/wheels, AND NOT the lower-profile all-steel ones that basically use a roller-bearing's outer race as the "wheel".
B) BECOME familiar (enough) with the underside of the load that you know where and how to BOLT your skates firmly to it!!!
Cannot stress this enough!
A(ny) skate retained only by gravity and friction WILL depart on it's own independent advice even on what you THOUGHT was a dead-flat and smooth concrete floor or steel plate. As all it takes to "unload" a skate is a stiff-enough load that "bridges' a drop of but 20 thousands or so of an inch and THAT truant skate is NO LONGER trapped by the load atop it.
If not practical to bolt directly to the frame of the load? Then go for a higher lift that puts space for a site-fabbed frame under the load - so the skates can be bolted to it to form a bespoke 'carrier'.
Either way, bolt 'em into place so they will 'be there' to take-up the load even when traversing a rather uneven surface. Expecting gravity alone to retain a skate where it needs to can become a poor-boy's imitation of a "suicide kit".
Not as if you had to hire a professional rigger twice every DAY is it?
Could be cheaper than DIY, just off the back of the speciality equipment you would have to buy... or rent?
2CW.. and over a dozen skates, several different types...