If not yet used in Discourse, which is still on Ember 3.10:
I have a strong feeling that the refactoring of imports is a step by the Discourse team to make the codebase octane friendly and eventually move to it…
A great blog series on Octane:
I’m starting to think that Octane is not a performance upgrade but a code simplification and structure upgrade but could be wrong.
UPDATE: It’s all those things. The performance improvements come from using Glimmer components. Someone is claiming 3-5x performance of Classic Components: Baseline performance of rendering components is "slow" - Performance - Ember.JS