Depends on a few personal factors also.
On the front something from 26,11 to 29,01 psi (1,8 - 2,0 bar)
and 33,36 to 36,26 psi (2,3 - 2,5 bar) should be fine.
I prefer to stay on the softer side on the front, because the suspension is (too) hard anyway.
Best do the test yourself. You will soon find out.
But why do you think that the michelin has better grip than the heidenau? Or where did you get that info from?
The Heidenau K61 won several awards in dry and wet conditions. Also the Heidenau K58 mod. is a very popular good tyre and well recommended in scooter tyre test magazines.