As for France, technically it is illegal to ever fill a stad alone cylinder such as the ones supplied by SafeFill which, as you know only have a single access point to the cylinder. I lived over there for 10 years building and running 2 exclusive adults only caming a la ferme's during which time I got to know quite a lot of dear old Johnie Gendarmes and this was an issue they were hot on, so as this was the case I had a long detailing chat with the boss of Gasit about the problem.
If you go onto the Gasit website
https://www.gasit.co.uk/gasit-vapour-gas-refillable-products.html you will see they can supply you with lengths of black high pressure hose, external wall mounted filling points, in-line lever open/closed valves and pigtails, all of which I purchased.
Although your van is professionally built, it is a very easy job to cut the required size/shape of hole into the sidewall of the van for mounting the filling point, then via a right angle connection point you should attach the hose which at its other end should have the valve with the pigtail screwed into the other end of it.
It is a bit of a pain, but when I want to fill up with gas, I simply swap over the gas regulator for the filling pigtail with the valve closed, then turn on the gas before opening the valve............. You can then safely drive to a filling station, fill up the cylinder, then drive away and park up somewhere before once again swapping over the attachments at the top of the tank.
I am sorry, but the best photos I have of my installation are these