Not sure. Could be different to go over as just a gasfitter then. I’m going on a state sponsored plumbing visa. It required all the paperwork etc then once that was approved by them an invitation to take a practical examination where you do some plumbing work, servicing a gas cooker, piping a boiler up etc nothing major. Your best bet to clarify may be emailing vetassess directly. I’ve done it a couple of times through out the process, they get back to you quite sharply.