I'll put it another way. It's like the dev saying, I'm going to build a railroad system that goes runs from downtown Manhattan, goes over the skyscrapers, does a few loop-de-loops, and ends at Yankee stadium. Dev person is a very skilled engineer and can absolutely build such a system, but everyone says to wait until it's built for testing before we talk as a community about whether we even want a system with that functionality, or if there might be some unintended consequences?I think your premise is not correct: There is nothing in existence. The new features are neither rolled out to mainnet nor testnet. Currently it's all on Evans/Udjins local source code repo, anyone could implement his own (better?) solution. As soon as Evan commits his work to github it's free for review, discussion and changes - the same would apply to any other implementation.
Who was talking about fixing bugs? Core team is currently working on 17 different projects (https://www.dash.org/forum/threads/march-2016-dash-core-team-monthly-report.8687) - pick one.
I don't get the point tbh.
Under what conditions should Evan or core team engage with the community about feedback over design plans? Is there a way we can foster a dialogue with actual core team devs without wasting Evan's or everyone's time?