I noticed, that only first database is loaded before component is removed, so I looked inside.
In script TryAddDatabases and TryRemoveDatabases called with second parameter of "onePerFrame", but the parameter is called "immediate", so it should be called with "!onePerFrame" instead.
When I toggled "One Per Frame" setting it worked as I wanted - all bases is loading on start in one frame.
So it's the bugreport about two things - OnePerFrame is reversed and if you want to load one per frame AND toggle "Once" only the first base is loaded
