> How about the official Scala compiler? It seems to stagnant a bit

It is. Odersky is spending most of his time on Dotty these days and he doesn't seem that interested in Scala any more, except when he's obligated to talk about it at keynotes (and he tends to talk more about Dotty there anyway). Despite the grandiose plans of possibly back porting Dotty features to Scala at some point in the distant future, Scala has been in maintenance mode for a couple of years now and with more and more people leaving the core team, it's probably going to stay this way.

Such a missed opportunity.