I wonder if Gas Safe have introduced similar constraints for plastic clips used with either plastic or copper pipe runs?

Well the relevant standards in the UK do not permit plastic pipes in fixed indoor gas  work, only underground.  (hoses for free standing appliances tend to be  butyl  or nitryl rubber, which will combust at high temperatures)

While metal clips for gas pipes sound like a good idea, while we allow soft soldered joints indeed prefer them over compression fittings, there is a problem at well below wall ignition temperature, as the solder at the joints melts at about 230C.

Actually in some parts of the world with more gaswork than the two or three appliances per house common in the UK,  hard solder (more like brazing temperatures of 600C or so ) is required for domestic pipework, and soft solder has gone the way of the old lead pipe and is no longer permitted.


In practice however, the accident rates are comparable, falling gas pipes are rare,  perhaps partly because there are far fewer gas pipes clipped to ceilings than there are cables.