I tried running the plugin for a few hours and experienced severe slowdowns with the Backlinks tab open in the sidebar and notes containing lots of backlinks. It seemed a few times unlinked mentions were being calculated, although I never clicked on the Unlinked mentions title.
I also saw this error pop up a few times. The note referred to looks like a run-of-the-mill note and loads fine.
Error while mounting Better Search Views tree for file path: 00 meta/05--css/edi/img highlight.md. Reason: Error: No section cache found in 00 meta/05--css/edi/img highlight.md
at createContextTree (plugin:better-search-views:4483:15)
at Patcher.mountContextTreeOnMatchEl (plugin:better-search-views:4680:25)
at e.eval (plugin:better-search-views:4643:23)
at e.wrapper [as renderContentMatches] (plugin:better-search-views:4219:20)
at app.js:1:1242238
at app.js:1:1198807
at app.js:1:236999
at Object.next (app.js:1:237104)
at a (app.js:1:235822)
reportError @ plugin:better-search-views:4668
Turning off the plugin and closing/opening the vault brought the speed back to normal.