I requested this just a few days ago 
Then googled a bit if this existed and found this function in Reaper. Give it a looksy. It’s called sub-projects.
I always thought about Reaper being this free open-source style audio editor for programmers and tinkerers. Much like Audacity, which I hate. But boy, this software came a long way. It’s of course, no longer free, but most of the features I asked about here can be found in Reaper. Movable Fades, Clip FX, Subprojects. Then I wanted to know if featurs I love from Nuendo were there, too. Media Bay, batch render multiple markers out to files and name them, naming conventions, surround setups, Macros, VCAs that actually work, dockable windows and solid window management that actually works, savable window layouts that actually work 
… all there. I only hate the design, native plugins look soooo dead ugly. But I hear more and more people, sound designers, musicians etc. switch over to it because it’s apparently so flexible. Depending on how much you want this feature, you might consider a look at the other side of the fence, where the pastures are always greener
Of course, there are also crucial things missing. AAF being one of the really painful ones.