Swift Select (Fiat Ducato) towbar

I've been looking at the options for putting our bikes on the back of our 2021 Swift Champagne 184 motorhome (basically a Swift Select 184), which is based on a Fiat Ducato panel van. It's pretty much down to fitting a towbar, then either having a towbar mounted bike rack, or a trailer.

Witter have three towbars, two of which are in stock:

https://www.witter-towbars.co.uk/towbars/fiat/ducato/van/59/250-inc-maxi-inc-facelift-7000

When I first looked a few weeks ago, the cheaper one was listed at £512 - Z11 towball, 7-pin electrics and no software upgrade necessary.

When I looked a couple of weeks ago, the price had dropped by £11 (great) but it now "requires a software update to activate all additional benefits and safety features". Witter can do this for another £72.

Has anyone else recently had a towbar fitted to a similar vehicle? Anyone want to hazard a guess at what's changed over a matter of a few weeks? Or what happens if we don't have the software update? Does anyone know what the July version of the software does that the June version doesn't? After all, if we'd had the towbar fitted a month ago, no software update would have happened, and it would still (now) be running one whatever it came with when we bought it in June. And it would all presumably be working fine. Or would we have by now had a recall to update the software? Or is it that whatever electrickery comes with the towbar itself has been updated, such that it will now only work with the most up to date version of vehicle software? Or might it just be that, in Witter's database, Fiat now have a new version of the vehicle software, and tells you an update is available, regardless of whether or not it's necessary? What might the "additional benefits and safety features" be?

After all, I'm sure new versions of vehicle software must be released all the time, and I'm also sure that not every vehicle on the road is running with the most up to date version available? Certainly not at £72 a pop...

And yes, I have asked Witter - and got no response.

Thanks!

Dave