I have been running a chainline on my Nomad that is about 5mm off without any noticeable adverse affects.
In my case, I wanted to run a double crank with a chain guard (or bash guard) in the outer position, the chainring in the inner position. I use a square taper setup, thus it is easy to adjust chainline by buying different spindle lengths. If I had bought the ideal spindle length for an optimum chainline, my Q factor (width between pedals) on my Nomad would be about 10mm wider than on my other derailleur bikes. I did not want a wider Q factor, so I intentionally bought a spindle 10mm shorter, thus the 5mm chainline error.
I have never run a hollowtech crank, can't comment on that. I have no problems with the UN55 bottom bracket I am running on my Nomad, I have a fairly long half inch drive ratchet and also a long arm torque wrench, both give me plenty of leverage when tightening or loosening anything that uses a half inch drive wrench, such as the tool for fitting a UN55 bottom bracket.
The only difficulty I have had with my crank or bottom bracket removal has been that I fitted self extracting bolts on my crankarms on my Nomad. And the self extracting part that was threaded into the crank arm loosened up and was lost. Since I have to remove both crank arms to fit my Nomad in an S&S case, when I went to pack up my bike at the end of a bike tour, I had to move my self extractor from one crank arm to the other crank arm and I did not have the proper tools to do that. Thus, I went back to plain crank arm bolts and will carry a proper crank arm removal tool on future bike tours with my Nomad.
Good luck with your plans. If you run a triple or a double crank but with only one chainring, you would need the spacers that take up the space because your chainring bolts are sized for two chainrings, not one. Do you have those? When I bought my Rohloff hub in 2013, those spacers were included with the hub. A good bike shop should have spacers if you need them, although they might not be the exact same thickness as the Rohloff ones.