During the MongoDB 5.0 release cycle, code under active development has been tested less often (in terms of compute hours) than the code which isn't. Notably, the InMemory and the large transactions format variants do not have 'all feature flags' equivalents.

I really want to emphasize that continuous integration means switching the feature from off-by-default to on-by-default is a non-event because the feature has been slowly expanding its testing coverage over time until the flip.