Backlinking using the Unlinked Mentions list (“Link”) clobbers the casing of the original text.
Unlinked Mentions list:
Casing clobbered after linking:
What I wanted:
Perhaps solved using a toggle in the Backlinks plugin configuration to maintain the original casing of text when creating Backlinks via Unlinked Mentions.
In case it helps any future readers of this thread: this seems to be how the app currently works. Case is preserved on the linkified text, and [[Test]], [[test]], [[TEST]] all point to the same note.