This is in an old house with large plaster medalions
Without a more specific description of the age and construction of the house, what I'm going to say is only a generalization.
The original gas light fixture, that the gas pipe povided fuel for, simply hung on the end of that gas pipe. Hanging an electrical luminaire off that gas pipe, whether the gas is on or off, will not present any more stress on the pipe than the original gas light.
The presence of the medallion, to me, hints at historic significance that, if at all reasonable, should be preserved,. . .so hacking at the location to quickly get done may not be practical. Rather, the client can likely understand, and value
, that marrying contemporary material to a historic system will take more time in order to minimize collateral damage.
Over my career, I've worked in a lot of old dwellings that were first lit with gas. As the building aged and the availability of electricity became reliable, the gas fixture was removed and replaced with an electrical unit. In some cases, the homeowner would seek out and install fixtures manufactured to provide both gas flame light and electric light
. IMHO, the finished surface appearance of rooms that are from the gas to electric conversion period, if still present, are of significant historic importance and valuable in its own right.