I was thrilled that Gambia has issued this 50th anniversary CEPT stamp, and I would say 'Yes' to adding countries outside of Europe which have such stamps.
In this case, the 2 members Marie and Wilhelm travel between Gambia and Germany, and since February I have drawn their address 6 times, 3 times to Gambia.
Postage from Switzerland within Europe has risen to €1.80 and outside of Europa to €2.30 which is why I have to cut down the amount of cards I send. Nevertheless, I sent the cards to Marie & Wilhelm in Gambia always hoping I would receive a postcard and stamps from there. So far, however, all their cards came from Germany. I guess it's my bad luck.
In general, I think the more countries we have the better it is for the club.