How can we have meta-discussions that are targeted at concrete actions?

Decide beforehand what you want the meta-discussion to achieve.

So instead of "Discuss how we hold meetings." make it "Come up with three concrete changes to how we hold meetings that we will test out within 1 month from today." or "We spend too long at the start of meetings deciding what to discuss and just saying 'take it to the list' isn't working because lots of people at meetings don't participate on the list. Discuss possible ways to improve on this specific situation, pick one to test out, and measure if it actually reduces initial dither time."