Hello Tim,
thank you so much for the detailed response.
If I understand you correctly there is currently no proper method for composing a large scene out of smaller chunks, which have got their static lighting already built and without that lighting information being affected once they are brought together for the final game.
I will try your suggestion and bake lighting for the levels individually, then come back to persistent and load them from there, though. Might give me the result I am looking for.
Thanks again, and also for your other answers all over the forums, which have also helped me in other cases.
Constant