Not exactly this mod, but in the parent mod Schall Tank Platoon under mod options "Vehicle clone placement on built" and "Vehicle clone placement on pasted". (But enabling this mod means the parent mod should already be enabled.)
When such "vehicle clone placement" feature is activated, the script will try to place the same set of all items (fuel, ammo, equipment, inventory, filters) of the reference vehicle onto the target vehicle.
My script is not limited to specific types of wagons or vehicles. However, it is hooked (called) by game event on_entity_settings_pasted.
So in case the game does not apply copy/paste entity settings and thus not trigger this event, I can do nothing about that. (For example, 1.0.0 Spidertron type does not trigger it. This will be triggered only from 1.1.0 onwards.)
I have not explicitly tested with artillery wagons with grids (I do not have mods with that). But at least I am certain that "Vehicle clone placement on built" feature works for vanilla artillery wagon, so I assume it will works for your grid equipment on modded versions of artillery wagons.
There are detailed instructions on how to activate this feature on STP FAQ, in case it is not straightforward on how to use that.
