What is working
Signed, because it costs nothing to own praise of the work.
Ask three questions.
Everyone answers. Decide what to do.
A retro board that works the same on a laptop and on the phone in someone's hand. No accounts for the people joining — you share one link and they are in.
What needs attention
Unsigned by default. People say the useful thing when they have cover.
Shoutouts
Always signed, and addressed to a person. An anonymous thank-you is worth nothing.
You run it in four moves: everyone writes, everyone votes, you talk down the list, and what you decided becomes actions with names on them.