We're not allowed to tell non-electrical-pros how to do actually do wiring, but I'd say it should be no problem, as long as the insulation involved is all rated for the highest voltage.
And since the 50 Hz is not coming from a utility service, it is likely that it is not necessary to uniquely mark the 50 Hz to distinguish it at all intermediate access points. But it would still be a good idea.
At this point I am closing the thread.