Double strokes in odd groupings

Kiko Freitas recently posted this exercise in which he plays a double stroke roll in groupings of 5, 7, and 9.  In the post Kiko points out that this is a good way to develop technique and internal time.  I also find it helps me hear - and more importantly, feel - odd note groupings and visualize them in different ways as with each odd grouping you'll start once on the first note of a double on each hand, and once with the second note of a double on each hand.

I would start by spending some time with each tuplet, but once you start to get comfortable with it you can try a bar of quintuplets, a bar of septuplets, and a bar of ninelets (nonlets?), and then work your way back down.