Huh, thanks yeah that does switch the binary to rga, but with rga you need to specify a wildcard operator for the path parameter in order to search PDFs, otherwise it only searches plaintext files, and I'm not sure how to make rg.el's RG function add that... must be a variable but not finding it.

  (use-package rg
    ;; ripgrep
    :ensure t
    :config
    (setq rg-executable (executable-find "rga")
     rg-buffer-name "rga"))