I wonder if all of these drawings etc are about a Trickle charger or a regular charger? I believe it is for a Regular charger as shown in my Maserati 2019 - only with the power cable as per the picture
I have both at home a normal regular charger that has 20amps output and the small trickle charger with 5amp max
generally, a small smart tricker charger is to maintain the batterie level ( which controls the power, stop charging, give impulse to know the charge, .. go in charge if needed, stop the charge etc.. by cyles )
a regular charger is to charge batteries that are dead, once they are full it must be disconnected ( it is pretty fast charging) leaving it connected for too long kills the battery.
Also, I am astonished that they request in US to connect a charger to the IBS, that's madness, it is cheating the process of the IBS, you connect the minus directly into the ground of the car, the role of the IBS is knowing the charge and discharge the temperature, the charge % in the batterie etc, so we should charge the batterie as the alternator does, and let the IBS do his job which is focused on the batterie itself, the IBS will record information like the % of the charge in the batterie, temperature etc, maserati dealer can access that info with their computer
a bit like that ( charge status can be from the alternator or any other source like a tricker or regular charger etc
if you connect the charger directly on the IBS ... it will show 100% as you by-pass the battery status, which is false.