Won’t it be interesting when our model of physics is updated to explain these cosmological phenomena? Who knows what new technology will be discovered as a result!

My brother once jokingly suggested that Dark Energy is the waste product of the power sources of alien civilisations.

(Neither of us is a physicist, but it’s an interesting idea for a short story).

There's a very old short story I've never been able to find again that beat you to it.

Every civilization that discovers FTL travel contributes to a more rapid expansion of the universe. The older civilizations beg them to stop, but inevitably they fail.

That sounds like a fun read. I’d love to know the title if you remember.

Sure, just so long as the pixies don’t interact electromagnetically, or strongly with each other by anything except gravity.