PhilipG,
Majority (58%) of F-35 maintainers aboard carriers will be RAF; the same percentage as the pilots operating them. All light blue will be fully trained to operate aboard a carrier - full flood damage control duties, firefighting and emergency procedures as well.
For the the "mixed buy", the specifics of how spare parts pertinent to each type are segregated and managed are yet to be finalized, so it is too early to speculate on what that will look like, especially as there is time to work it all out.