A foundation full of warts belongs in experimental. I don't know how by your own confession of the house and the sub-basement not yet being finished doesn't instantly mean it should have stayed in experimental.

Your assertion is that it was "rushed". And yet here we are today, talking about how much we wish were implemented. That's not rushed--that's the polar opposite of rushed. Almost nothing about what we currently have on stable would have been better if it was still percolating on nightly, and would have the downside of having almost no feedback from real-world use. I remember the pre-async days, nesting callbacks by hand. What we have now is a great improvement, and just needs more niceties stacked on top of it, not any sort of fundamental overhaul.