11. https://github.com/bevyengine/bevy/pull/13762
And this is a *nasty* regression, caught during the release candidate process. We managed to break event (and RemovedComponent) double-buffering, by adding an extra flush to subapps. Turns out this was intentional to make sure that the render app can use RemovedComponents correctly.
Ahhh tech debt. I expect that pretty much all of the concepts here will be gone in a year lol, in part due to nonsense interactions like this. Good tests, good fix, merge conflicts