Just wanted to follow up on a more positive note here. While default main actor isolation impacted a bunch of our libraries that optimized for data races by adopting sendability more places, we’ve found that relaxing sendability requirements have improved things and we can support both nonisolated and main actor isolated use cases without much trouble, and in fact we’ve been able to make improvements thanks to isolated conformances. (Our only worry is a few soundness holes we’ve found, but hopefully they’ll be plugged soon!)