Every past dueling build has had issues that could be fixed, but were instead overlooked. A revamp occurred, and new issues where introduced with it. The best way going forward is to do what should've been done long ago (8 years or more?) and simply stabilize, fix issues and build upon a solid base.
Reverting is not a fix-it-all, because there is always a reason why a beloved build from the past was changed. 1.3 had massive issues, all the 1.4 builds as well, had issues. 1.5 had issues, 1.6 to 1.10 had issues... and oh boy does R20 have issues.
I hope everyone will realize by now that reverting will not fix anything. As time goes by, people forget the flaws and annoyances of past builds. Of course, R20 is one of the most flawed and bugged messes we've ever had, but it can be fixed, starting with bugs and obvious problems. The community has already drafted a nice list of changes that, if implemented, would go a long way towards a stable and playable build.
My personal opinion is that a system so heavily infested with arbitrary ACM bullshit, like R20, is not the best fit to build upon, but it can be made to work if the necessary changes are implemented. It was impossible with the previous saber dev because he refused to implement such changes, believing in his own vision over that of more experienced duelists.
I think that defiant, and whoever ends up overseeing the fixing process should be transparent about what is going on: this would provide hope for a community currently left adrift due to a very badly implemented patch. I've never seen this kind of drop off and reaction to a new patch before, and we haven't even addressed the death of open mode. Something should be done immediately to re-establish confidence in the dev-team after the disaster of R20, so that people can have hope for the future instead of being quietly ground down and leaving the game. I suggest having a dev meeting or two, figuring out a game plan for how to fix, and then letting everyone know with a public announcement.