I consider releasing 5.4.10 in its current state, then proceed to release a new 5.5.x with these 5.4.10 fixes, then maybe release 5.6.

But it seems there are still some regressions in the backlog:

• Different SQL Generation About Many-To-Many Relationship With Filter after 5.2.0 #3652 (would be 5.2.0 regression, with a test case PR failing on master)
• "No persister for: NhibernateTest.Entities.CustomDateType" When performing a query for the 2nd time #3669 (would be 5.4.0 regression, with some code for reproduction)
• Maybe Collection cache lookup failure with enum keys #3643 (would be a regression somewhere between 5.2.7 (excluded) and 5.5.2. A PR provides a test case.)

The thing is, few people seem to have time looking into them. So, it could delay considerably the releases if we wait for these issues to be fixed or rejected.