An offsite is expensive in both money and calendar time, so the measure of a good one is what the team does differently the week after. Build the agenda around a small number of real decisions.
Give each agenda block its own board so the output stays separated and each block ends with its own summary instead of a single wall of notes.
Open the boards a week early and let people add cards as they think of things. Offsite time is for discussion, not for staring at a blank page.
A card without a name attached is a nice thought. Close each block by turning the top items into commitments with a person against them.
Plan fewer blocks than you think you need. Three or four substantial sessions across two days, each ending in a decision, beats eight sessions that all run over and resolve nothing.
Share the board link before the offsite so remote or absent colleagues add cards in advance, and send them the AI summary of each block afterwards.