Thanks.
FYI for others, we solved this using Support's suggestion plus some more.
Two panels in a VP, in vertical.
The top panel is a search form. The bottom panel is the search results.
The User can search and filter in the top panel, viewing the results in the bottom panel.
On the bottom panel we have a process that is applied to multiple items. So the User can select all in the search results by using the top click box (and deselect some if they choose). Then apply the process to update the status on all selected instances as described by support below.
It works great.