As you know, Asset Review rounds do not assign assets to anyone, they just store their interest or disinterest in items. There's no need to delete any rounds -- we can do a second Asset Review round, with only one caveat: all assets that haven't yet been distributed are always selected to be part of a new AR round.
You as administrator do not get asked, when creating an AR round, what assets to include. The system selects them automatically. To be clear:
- assets already assigned to a divisee are not included,
- assets with a current destination of "Divide" or blank get included, and
- assets assigned to any other destinations (such as "Sell" or "Donate") are not included.
Therefore, assets not yet divided will appear in the new AR round -- and they could be appearing for the second time, in which case the previous selection of Yes or No will appear to each divisee, allowing them to change it if they wish to change it.