That's completely normal, doesn't matter SRAM / Shimano etc. I've measured the movement of many combinations of rotor and hub for play. DT hubs are actually some of the loosest, and Shimano's low end hubs the tightest.
If the rocking really bothers you, then I have experimented with coating the hub with a PTFE spray and then putting an epoxy between the rotor and the hub. Means you can still get the rotor off when it's cooked, and the hub stays clean.
I loathe the play in some centrelock combinations.
I like your epoxy Idea!
I've been using layers of ptfe plumbers tape around the hub splines to take play out.
It gradually comes back as the tape compresses though, but easy enough to replace the tape when cleaning rotors
Have you noticed any difference when using the ptfe tape? In my experience, there's always some movement of pads on pistons anyway, so completely fixing the centrelock doesn't make a huge difference.
That's completely normal, doesn't matter SRAM / Shimano etc. I've measured the movement of many combinations of rotor and hub for play. DT hubs are actually some of the loosest, and Shimano's low end hubs the tightest.
If the rocking really bothers you, then I have experimented with coating the hub with a PTFE spray and then putting an epoxy between the rotor and the hub. Means you can still get the rotor off when it's cooked, and the hub stays clean.