OTT? maybeSeems a bit ott?
We do a lot of work on boilers, wiring them up, changing pumps etc, we are not “Gas Safe” but we have no problem at all with various councils/local authorities. We obviously avoid the gassy bits
But it's down to responsibility. Just because I haven't broken into the gas system doesn't absolve me of blame if there is an unknown gas leak on something on that system. It's a very grey area, and one I would rather not get dragged into.
If your public liability covers you for that then thats fine, but mine doesn't anyway (mainly because I said I didn't touch anything with gas).