@Dietmar
I was unable to find any PDB symbols for the 8118 beta build of storport, but I did find them for the earlier 8102 beta build.
Can you debug this when you have the time?
The F7 BSOD I'm sure is because of security_check_cookie function, but the subsequent 7E BSOD isn't so easy.
I'm hopeful you will find a way to get passed it like you did with the ACPICrackPRT function before we had the source.
storport_6_2_8102_test.7z