This fixes the issue in the notebook

[hannorein]

I don't know if this is the right solution!

[hannorein]

Note that REBOUNDx used to use dt_last_done for this effect. See e.g.

reboundx/src/modify_orbits_direct.c

Line 87 in 0c1c373

const double dt = sim->dt_last_done;

[hannorein]

Maybe this is obvious, but why does this effect not work at all (not change to orbital parameters) for integrators other than IAS15/WHfast? E.g. BS, SABA, leapfrog.