Ok, the multi limiting didn't work but then i found a separate Turbo setting. After disabling it, system booted while i still managed to keep existing 4,2GHz @ 1,35V. I don't need some stupid multi bumping if i have 4,2GHz at disposal anyway.
Checked the C states with your custom RealTemp and C6 shows 80 pretty much right after the boot. So now i have all the power saving features enabled and still a very respectable 4,2GHz clock when heavy processing is required. I think this should do the trick
It's always nice to have someone around who knows in-depth stuff like this. Thx again unclewebb!