I reckon HIVE would be an excellent fit for El Salvador. The BTC price is getting to a level where it's great as a store of value, savings plan and government asset, but that very volatility is a disincentive to using it as a currency for day-to-day transactions.
HBD has the advantage that it's denominated in dollars, which will be a familiar value scale for Salvdoreans, and with no fees when you exchange/spend them, it's ideal for small businesses wanting to offer their customers a way to pay.
If the dollar wasn't already officially legal tender in El Salvador I'm sure a lot of citizens would be using stablecoins to escape the local currency.
El Salvador is already ahead of the game by having the dollar as the official currency, and Bitcoin to replace it when USD inflation gets out of hand.