I had no idea those other extensions existed.
Been thinking of similar but we don't have anything other than .ca - I think there is a .Quebec but it's rarely if ever used.
I've been thinking about just .ca for Canada and then only Canada flavoured .com's like domains with the word maple, or Canada or anything referring to something within Canada.
So in your graphic above PhilippinesForum.com would not be eligible because it is not Canadian (or in your case UK).
It's a conundrum for a ccTLD site because you want to keep the focus on the subject at hand yet you also want to allow matching .com's to your members names (our in your case the stated extensions above).
Personally I like seeing the sites stay focused on what they are, or they basically turn into another mish mash forum that tries to be everything to everybody instead of the ccTLD forum they were meant to be.