It might not be long. There’s only a handful of reported bugs on Pie, and we’re only on the 2nd beta so far. Xiaomi are probably a lot more careful now though, after the shit show that happened with Oreo.
Works really great, only problem I have is Disney+ is blank listed on it.
Nobody knows!, not even the beta testers, I'm one of many users who installed the beta manually and I'm still waiting for the next beta build to keep testing it until the final update is released.