Ideally after selecting and linking a group of several pieces from the PrP timeline and replacing with a comp and editing them in AE I'd like to bring them right back into PrP as they were or to put it another way I want to unravel everything the link smashed together and have back in the timeline as it once was with the added AE stuff.
I'm guessing this is impossible, but thought I'd check to make sure I'm not missing out on some cool AE export/ PrP import plugin that could do something like this.
After you use the Replace With AE Comp command, and After Effects is launched and creates the comp, immediately undo the command in Premiere Pro. The DL'ed comp will disappear, the original clips will reappear, but the comp as created will remain in AE. You can simply drag the comp from AE into Premiere Pro, and then you've got the best of both worlds.
But no--you can't "decompose" a DL'ed comp.