the thorn TestMoL (for the CactusTest arrangment) exercises most of MoL's integrators (not the Adams-Bashforth ones yet nor the generic one since they are "different").
It would be useful to include in the ET to have a basic test of the central ODE solver.
The thorn is currently in incoming
svn co https://svn.einsteintoolkit.org/incoming/TestMoL
it contains test cases (that's the whole point) and some documentation. I have used it to test the recent MoL commits and found two outstanding bugs that way.