Thanks!
I had the problem that I tested old conversion from saved scripts, not from the BD3D2MK3D GUI, because they are specific. In the mean time M$ had changed GUID or I used another machine (created new power plans...) and the old GUID strings did'nt work anymore.
With aliases it worked again without starting the whole BD3D2MK3D conversion.
If you create a new power plan then it gets no alias, I know that. I don't need new power plans, I only wanted the High Performance visual back. That works in the latest Win10 with a copy -- and new GUID...
Yes, the High Performance power plan is hidden, not deleted because of a big number of hardware drivers that uses it.