Okay so I did a few tests.
Jeweller's scales on the bed G30 - 15g required to trigger the piezo probe. So not a heavy hit.
I don't have blue painters tape but I have got some white masking tape and I read there is no real difference except blue tape can be removed after it has been attached for longer than white/cream masking tape. It was the first time I have ever printed onto tape, or onto a cold bed! I've always had machines with heated beds.
I had to add 0.2mm z offset in slic3r (so thats G31 Z-0.2 in duet config.g if you prefer to do it that way) to get a perfect first layer with the tape. But I had to use the same offset without the tape printing onto relatively hard print bite.
I used G30 after autocalibration, with the bed at 0 with the tape and 80 deg C with printbite. The nozzle was at 130 deg C for probing both times.
So either the bed temperature change is having the effect of compensating for the thickness of the tape or the tape isn't really making much difference to the probing.
I measured the thickness of the brim in both models I set a 0.36mm first layer height its was 0.35mm for tape, and 0.35mm for no tape.