As far as progressivism and quotas, I simply can't argue on this unless you give me a specific progressive tendencies. If you're talking about US progressives writ large then the main reason quotas are so popular is because the people in power that put those quotas in place, which often weren't even progressives, found quotas to be easy to implement as other solutions are very difficult and inconvenient for those in power, though popular.
What you assert as proof that "it worked" was, if I understood your "30%!" correctly, an increase in equality of outcome.
How does this square with your claim to favour equality of opportunity, not outcome? Doesn't it show that what worked was what you claim not to favour; why would you crow about that?
As for the 2nd point, that's more of what I'm getting at; that core populist/mainstream progressive movement. I could certainly believe that the leaders are jumping on it purely due to, as you say the simplicity and popularity of them.
As for your university efforts I'd have to know what those actually were before making a call.
And re progresivism and quotas; it isn't based on it but it subscribes heavily to it due to its utility.