Add the option "Use regular expressions" to the other three options to search in PDFs ("Highligh all", "Match case", "Whole words") would be a very nice feature.
Ah you are right, I just found it, here's a screenshot of the exact setting in the "Advanced Search" window (it is pretty hard to find): https://imgur.com/a/ngHlWSr In Zotero it is called "Regexp".
https://imgur.com/a/ngHlWSr
In Zotero it is called "Regexp".