pocket dimension thing

That’s “The Void”. I think we’re all in agreement that’s one of them.

Malon were dumping their toxic warp waste

That’s “Night” and I just remembered that one and edited it into my comment. So I guess that is the second one.

the section of space that was dark and many light-years acros

I’m pretty sure that was a nebula. “One” was the episode name, I think?

I should prob throw VOY on in the background. Good enough excuse as any, right? lol