Hi team,
I've made the requested changes and improved the tests.
The tests heavily depend on the environment's performance so I won't put them to the PR CI (it's in tier2 now and it requires to run it with DB_LOCKS_MONITORING_ACK env. variable)

Please, review:
https://github.com/389ds/389-ds-base/pull/4762

And the design doc review can be found here:
https://github.com/mreynolds389/389wiki/pull/56

Sincerely,
Simon