Thanks. I’d read the thread on adding the clock and it isn’t exactly SDD101, is it! But I thought that the key and the light settings might be fairly straightforward as they’re not modifications but are things that the system is designed to do rather than being hacks like the clock.

I shall proceed with caution!

As I mentioned in another thread, I've just tested out my newly acquired 'MongoosePro' cable and V130 SDD. Initially I had a CTEK charger hooked up to the battery (which may be as old as my 2008 model FL 2) and I was able to poke around the various menus and even tried the option for tilting mirrors when in reverse (it didn’t work as I don’t have memory seats). However when I came to add my trailer module, SDD said that it needed 12.6v but I only had 12.4v (I think those were the numbers). So I hooked up a substantial 20A Ring charger ( https://www.ringautomotive.com/en/product/RCB320 ), set it on fast charge and on retrying adding the trailer module SDD said that I now had 13.2v and all was well.

So perhaps a heavyweight charger is sufficient for most SDD purposes? This particular Ring one is a really heavy one so perhaps is better able to provide the sort of power needed than a lightweight one like the CTEK.

P.S. I also programmed a new key after attaching the Ring charger and it worked perfectly.
P.P.S When SDD said I didn’t have enough voltage it also said to attach a Jaguar approved battery charger, not a battery support unit.

OK! So this thread has been very informative and has raised some interesting points on the need for a BSU. With all that taken on board and being in the right place at the right time I've managed to pick up a very good used condition GYS Flash 100 for a fraction of new price.
Thank you for all your advice.

I use a CTEK 10 amp on supply mode on my Evoque. Looking at ordering the CTEK 25 amp soon.

Depending what the voltage is to start with, I'll charge it for an hour or two before hand. Any changes I'm going to make to the CCF are well planned and I'm in and out in no time.