Have a 2018 xt with 28k on clock, just coming up for 4th service and asked dealer about cvt fluid change. Was told lifetime fluid and doesn’t require a change ! Have read on forums it does require changing so am a little confused. The car has 80k or 5 year warranty on running gear so not concerned at moment. Any thoughts or experiences with cvt fluid change would be appreciated 

Yes, I queried that when I got the Outback and was told the very same.  It's curious because, at least with the OB, in Japan the cvt oil is changed every 36000 miles, in Canada I think it's 50,000 and it's something else in the US (sorry, can't remember the mileage).  Why isn't it sealed for life in these countries? Climate differences - humity? Local eco laws about oil qualities? I don't know.

This guy, John Cadogan, has a Youtube video on the 'sealed for life' claim for CVTs. 

Sealed for life! CVTs

He's a bit brash and likes to hear his own jokes, but if you can bear these idiosyncrasies he has some good auto knowledge (see the towing weights vids for example).

Like you, I just managed to get one of the last vehicles with the 5 year transmission engine warranty, before the 'new' 3 year warranty came into play.

Bottom line is that while there are some complaints about the cvt systems, given the number of Subarus sold over the years, and the massive mileages some of clocked up, there's not a lot of complaints.  Consequently, I'm not losing too much sleep about it - for now 🙂 !