your not covered
Also a panel can be defaulted etc when its got a support contract on it, reprogrammed and the maintainer has all the liability without any control of how its programmed.
I do agree that systems (all programmable devices) should be defaulted on maintainer change. As above this can be foc or a site visit. I suppose its similar with locked phones.
An installer has invested in training, support and even how to make x work with y. That information and knowledge belongs to that person/company. The bit of kit belongs to whoever bought it and can be used how they see fit.
A lot of equipment now also has other passwords, security questions etc stored in it, remote codes all sorts. All this needs defaulting once the maintainer has lost control of it.