New LowerFpsWhenEmpty default value result in very slow startup speeds on fresh servers.
As of the new patch on 7/6/22 the new defaults for LowerFpsWhenEmpty (true) and LowerFPSWhenEmptyValue (1) make starting up a fresh server (specifically the map population phase) take upwards of 10 minutes.
Disabling the feature or raising the value results in it functioning as expected and starting up quickly.