[KMPrenger]

There may be less benefit of running a tune on a manual, but you should still have gains, even if they are not immediately noticeable. If anything, it may take more miles to really kick in, but then again maybe not.

As for the issue with the engine rpms, I'm sure it is the ghost cam as you have already mentioned turning off. I never really trusted the ghost cam as being completely safe, so I opted to get my tune without it.