So I was thinking what if we could make repair trucks actually have a slow "armor patching" repair function over time to only the hulls of vehicles (wheels treads engines and turrets damaged or destroyed are not fixable by repair truck) inside of the radius circle? Turning on and off this feature with a button is a good idea for when you would rather use a repair kit with more efficiency.

Perhaps a second option would require engineers to be present in the vehicle that needs repairing (you would still need the repair truck in radius to issue the repair kits into the inventory of the engineer inside the vehicle needing repairs.) These "alternative" repair kits could effectively be used only over time prescribed from the truck.

Next idea: A vest that opens a second inventory when equipped (like men of war, you can equip a body armor in the main inventory) that takes priority over the type of equipment that generates from using a supply crate or truck, based on the VEST (not the guns in inventory of the player unit).

The benefit of doing this keeps the space available in inventory so that tactical choices of inventory are not disturbed by spamming chests.
Heres why- lets say you have a machine gunner vest equipped. Visiting a crate puts then boxes of MG belt ammo into the vest. Leaves the main inventory alone so it does not fill.

Two options for deployment. One: the type of unit initially comes with a vest of a certain type. You can get backup vests at a certain type of emplacement that acts like a armory where you must send "use" the emplacement with the troopers selected to gain the vests for the type of vest the emplacement provides.

And for the next option- that the role of the single infantry decides what type of vest it gets from the emplacement. Perhaps there is a way to gain the vest by dropping the vest of one type of unit for another unit type to equip it!

Either way the crate or emplacement would need to be used with the take button, to avoid spamming equipement (a good thing to avoid for some of us). Also a take or use button for putting ammo or equipment from the crate into the MAIN inventory when the unit is selected. This only works for option two. This is a backdoor so that you can keep the functionality of the vanilla system without spamming the inventory.