The delay is around 1 second to show the "Search Menu Bar Status Items" window. I think this was never instant, but since the upgrade to macOS 15.3.1 (24D70) I"m noticing higher delay. The items in the generated list are ~29 most of the time, so I guess because I have quite some items, this is slowing the generation of the window. I've also tried with 19 items, but the same delay.
Indeed, it seems to have gotten slower to retrieve these screenshots.
v5.236 (uploading) adds caching to workaround this, the items will be refreshed while the list is already showing.
Kudos Andreas!