Rigid base wins on uneven desks.

Yes, a rigid base helps a lot.

A hybrid pad’s hard base (plastic, aluminum, whatever) resists bending, so it won’t curl up or develop soft spots like a full cloth pad might. On an uneven desk, that rigidity keeps the surface mostly flat rather than sagging into the low points. You might get a little rocking on a deeply warped desk, but it’s still better than a flexible pad that turns into a wrinkled mess.

The trade-off is that a rigid base won’t conform to dips — you’ll feel the gap if the desk is really bad. But for typical minor unevenness, rigid wins every time. Soft bases just amplify the bumps.

If your desk is genuinely warped, fix the desk first.