The crash I referenced was caused by having the scrollbar enabled IIRC, and it was fixed earlier this year. It made it impossible to launch the main activity without crashing if you’d enabled that setting, so users were sharing workarounds to launch directly to the settings screen without loading any communities so they could disable it.
If Valve’s Employee Handbook is to be believed, they don’t use a formal project structure with static teams. Instead each developer works on whatever project interests them, and one of Valve’s current goals is to improve game performance on Linux/AMD by contributing to upstream open source projects.
Valve is as close as we’ve gotten to someone paying a bunch of industry veterans to contribute to open source. It’s amazing what happens when all innovation isn’t black-boxed in an internal repository and forgotten about.