I don't know much about BSM, but if you buy these coins from a trusted, authorized gold dealer, you can’t go wrong. I’ve seen them before and was thinking of buying them but forgot about it, now I’m reconsidering.
They are legal tender in the country they issued, if you are lucky at customs they could accept the value as the face value. When you want to sell though, expect the buyer to demand lower prices as resale is also harder
If you read the article carefully, they write about two theories and not about the fact whether it is legal tender at all… Most probably their conclusion is correct but who knows… Thanks for the article anyway!
It doesn't matter much, as long as it's real gold, you can use it for payment or at least exchange it for fiat currency at any gold shop if that's what you prefer.
The above counts only if you are bringing the coins over borders. Even if it is a legal tender, for the US$10,000 range declaration in some countries the face value and not the actual value is used
A friend of mine regularly purchases bullions, and ships them over borders. He always declares it at customs, as they hardly ever accept the nominal value but the market value. The EU has a list of approved coins (https://op.europa.eu/en/publication...68741-3c48-11ec-89db-01aa75ed71a1/language-en) which are VAT free - even 6 Somalian gold coins are there. But better to investigate and check before, the security check always could warn customs if someone wants to ship gold in the hand luggage