It is a bit bonkers, yet exists. When I remove a cooker (eg for another trade to lay a floor) I have to make sure that there is no accidental release of gas. When I asked gas safe in this they stated that a self sealing connection is not acceptable as a child can “play” with the fitting. Contractor removes cooker, just as a minimum has to ldf fitting and can leave as is.
I would have thought you only need CkR1 to “work” on the appliance - install, service, repair etc, but removing from a self sealing fitting is not regarded as work and normal check and relight should suffice. If it’s going back in the same place as long as there is no safety issue, eg scorch marks. I was even told by gas safe that there is no need to check to safety shut off (lid) as you’re not working on the appliance.
The work on meters is covered in L56 of the GSIUR as being regarded as gas work, if it was classed as meter work then I suppose you couldn’t cap a supply off, add a meter bracket or re-pipe from the meter outlet either.