Beef Shawarma works on triplet rolls at different dynamics and with different playing zones. Maintaining roll quality across the range of heights and around the drum head is crucial to playing snare drum in an indoor drumline, where discrepancies in sound quality at different heights, as well as discrepancies in precise bead placement, can dramatically impact the quality of the music.
A useful variation would be to replace the "edge" position with the "guts" position (2 o'clock on the drum head, over the snare bed) and perform the exercise that way. Matching sound quality between hands is a little more challenging at the "guts" position and while transitioning to it, since the left bead has to move slightly in front of the right in order to match distance from the rim.
If you really want to push your versatility, another variation is to reverse the dynamics (i.e., piano becomes forte, crescendo becomes decrescendo, etc.), so you end up doing weird things like crescendoing towards the edge, which creates an interesting sonic effect, in addition to forcing you to match roll quality at the high dynamic with very little snare response to support the sound and hide discrepancies in timing.
