So, I made a post here:
https://forums.cockos.com/showthread.php?t=244813 which details the issues at hand. Someone recommended that I make a post here, so this is that post.
The TLDR is basically that I would love to see a way to render multiple tracks simultaneously by finding the last piece of audio on each track, and then discontinuing any rendering of silence from thereafter so we aren't rendering minutes and minutes of silence causing extremely large files for no reason.