simMechanics: local solver not supported

When using different physical domains in a simscape model, I prefer to use a local solver for each domain, since some domains require a faster sampling time than others. When including simMechanics components, a warning is issued during compilation: "local solver not supported in simMechanics, global solver will be used instead". Essentially this means that the simMechanis part of the model will run at a stepsize equal to or smaller than that of the fastest physical domain. Clearly, this greatly increases simulation time. Am I seeing this right, or am I missing something? Does there exist a work-around?

Then I have a second question concerning this issue. From the warning described above, one would suspect that it does not make a difference whether the local solver option is selected or not for simMechanics components. I do however get very different results for each case. The simulation will run extremely slow when not selecting the local solver option. Wherein lies the difference?