Every journey starts with small steps, so these announcements should be seen in that context, although Bukele announced a few months ago that two more countries will do the same as El Salvador - in fact, these are two islands that would be hard to find on a map without google.
Is Prospera even an island?
Wiki says it's a special economic zone on one of the islands in Honduras, a city of some 10k on paper.
But I think Madeira is a bit different, yes it's small, it is poor by EU standards but still 5x times wealthier per capita than Salvador, it's a pretty well-known destination for a lot of tourists and it got twice as many tourists as Salvador, probably a far better influence.
Plus it's still EU territory, it has a representative in the EU discussions as well as two MEPs, it is inside the VAT area and the Schengen, pretty good.
At least we have something finally!

These are autonomous regions so their decision doesn't stand in the eyes of law of the governing country. For example, Madeira is a part of Portugal, so the laws of Portugal applies on that region. So if Portugal makes bitcoin illegal, it will apply to Madeira as well.
Not really that simple, as far as I've seen from their Consitution they have complete autonomy on administration as well as taxes and quite some interesting legislative powers till they hit the limit of national unity. Portugal is not that anti-crypto at all, they use the Euro so there is no pressure in that direction either that would have come if they would have used a national currency, so I doubt they will say much.
That free zone might be a thorn, I see there are some decisions about breaking EU state aid rules, but that's a different thing, not concerning
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