Interesting. The separate validation for Swiss EASA licence holders allows the operation of G reg aircraft both
inside and outside UK airspace. I was wondering why there were two separate validations and now it makes sense. Here's the extract for those curious:
The CAA hereby renders valid, for the purpose of operating an aircraft on the United Kingdom “G” register within and outside of UK airspace, such Part-FCL pilot licences that were issued in accordance with Swiss Law by FOCA, and which continue to be effective on and after 31 December 2020 by virtue of Official Record Series 4 No. XXXX.