Thanks for the suggestion.
The given header has RX/TX that can support very high serial data bitrates.
But anyway there are different ways to do this. The BT06 was a simple way to get wireless with a decent bench range, I suggested that since I tried it and it works, and it's easy to put in the box or attach externally and power it from the same header/3.3v that powers the CRanger.
You could also hook up an arduino with IR transmission to that header (read serial, convert to IR, decode IR on other end, output serial to your PC), I never tried it but I think they can have pretty decent data rates, but sounds more complicated and maybe things can go wrong - obstacles!
Optoisolators means no wireless, but can be used with high data rates as well, however I'm not sure this is appropriate to integrate into the CurrentRanger, maybe not everyone wants this specific arrangement.
But I am sure there must be some isolated USB UART converter out there (powered from external USB but isolated RX/TX). Or one could be made easily, still no wireless which is always nice. Does this option sound ok for you?