The suppliers must consider them to be compliant,as they fit them,albeit under some duress...due to cost and fitters lack of training,i would guess.
I would not judge any disruption,as a good enough reason,not to.
There is a very easy to understand,risk assessment,when considering the skills of a possible individual,and their possible reasons for needing to isolate,which the suppliers hear once,and simply fit one.
A great deal of the properties round here,are dual rate,from the sixties,and have all manner of "additions" and cross-overs,which include other circuits and single sockets,which are fed from the low rate meter.
The issues this can present,can best be mitigated against,by having an obvious,single point of isolation,an uninstructed person,can find easily.
