The reason the government gave us years ago why we couldn't have an EFP was because the rifle didn't need a licence in your home country. We could only have EFPs for rifles that were on ticket in England(and Wales) and any rifle below 12 fpe would not be put on ticket. We could not elect to put a FT rifle on ticket even if we wanted to, as a way of obtaining a EFP, because the demand on resources to administer the requests would overwhelm the system. That is what we were told, prior to the Polish Worlds.
On that basis, the only way you'll compete in a Scottish GP is to live in Scotland. NI residents might be allowed in as their rifles are all on ticket anyway, but watch the small print for the venue insurance, does it exclude rifles that are on ticket? On ticket in the NI sense encompasses all power levels including sub 12.