Thanks for the prompt reply Dave.
I suspect the vintage of the Unit is going to be the sticking point here. I have installed the new driver, but my iMac still won't recognise the PODXT Live. And I suspect that even if it did, if I need Gearbox or Line 6 Edit to send tones then that will be a dealbreaker as neither of them are compatible with OS Catalina - the most recent version of each of them are dated 2010 and 2014 respectively, and various forums are full of 'why don't they work any more...' type questions.
I have an old laptop sitting in the shed gathering dust. I might try to see if I can install something useful on that and get it to recognise the PODXT Live. Failing that I may just need to spend more time building my own sounds.
** While I am on here, another simple question: Is there an easy way to bypass the XT Live altogether (and I don't just mean de-selecting the AMP/STOMP etc). I tend to have a 'Pure' channel with no effects or modelling which I use a lot when I want to bypass the XT Live and have the signal go straight through to my amp, but always wondered if there was short-cut or alternative way to do it. Again, the user manual never gave anything useful on that front - any way you can think of?