... in fact, even if you consider Qt and KDE in symbiosis, you could say that KDE is the place you can do things that don't fit the narrower scope of Qt Project, and that calls for tooling that supports things gerrit doesn't support well enough. If gerrit is a constraint, then KDE picking tooling other than gerrit would arguably contribute to the combined ecosystem by making a resource available that is otherwise lacking.
Cheers, Eike
