[throwawaymaths]

That's a really bad bar, beacuse it creates a bootstrapping problem: There's a lot of very difficult math that you have to do to get to that point.

And if you say "don't take it seriously until it explains all those things" then why should anyone bother to do the heavy lifting for all that math?

Let me make a different suggestion: As soon as you have one or two very interesting observations that modern GR can't explain that are apparently gravitational, then you should start encouraging people to take it seriously and start working on the hard math.