Cheap to spawn (no more than 20 supplies honestly), small, maneuverable, all terrain, good visibility, no more than 1 crew and top speed of like 15km/h, on trade it has good supply capacity, perhaps 600 per forklift? so each would fill a vanilla truck in 1 travel, even if that'd be unrealistic, capacity to build minor structures like sandbags, stone blocks or concertina outside of bases, as well as push / flip capacities (for the upcoming push / flip feature) and wreck removal

It is a common issue that trucks can cause real chaos in bases, either get stuck cause geography (bases in woods, or tight layouts so can't turn well, like Vanilla Reforger Aarland Military Base), or in their attempt to load supplies run over someone who is just rearming at an armory, doesn't help that currently mirrors don't work. It's also a fairly known, although less common issue that sometimes when building defenses for your base, you need to place a wall of sandbags or a concertina just outside the base, but spending a huge ammount of resources on a construction truck ain't worth it either, not to mention, having to carry supplies from one spot to another, as different constructions in base are different storages and to (un)load supplies you need to be next to the actual supplies.

Well say no more thanks to your trusty forklift!! with a reduced top speed and being a single seater, it won't ruin the ballance of the game from people using them as transports , but at the same time, cheap enough for players to avoid using them. Base too cramped or in the middle of some woods? need a load / unload bay or landing zone 50 meters away from the base limit? just take your forklift to the nearest arsenal, maneuver around confident that you're not gonna flatten one of your fellow crayon eaters thanks to its compact size and wide visibility, then slalom around the trees and to your truck, load and move to objective!

Could also give it vehicle push / flip capacity filling x ammount of players, since I do know that's a coming feature on next update, so you can bring one to a flipped truck, which would normally require a large ammount and add some extra numbers, perhaps make repair truck being auto-flip/push. Perhaps even cleaner capacity, someone got their truck RPG'ed inside base and the wreck is stuck blocking everyone? get your forklift and scrap the wreck or something