All trucks give 3 points with short logs, with either the carriage or the trailer, but the zil 130 only gives 2, the carriage and the trailer. Im not sure if this a bug or a design decision, but it seems kinda weird.

interesting, old way the carriage (short log load) has always given 2 points regardless of the vehicle. medium load 4pts and long 6pts. so now just the zil has 2pts and the rest get 3pts? does seem a bit strange, but will give it a look later myself.

Its smaller "B" category truck, so it makes some sense... Its only vehicle from A & B category able to carry at least something, if I am not mistaken, so maybe there is a reason?

The short log trailer should have the same points while the actual log carriage could be kept at 2 points, but the load should be reduced by using just one short log and having a significantly reduced weight so that it can move with it's road tires and no diff lock option.

As it is right now it is mostly useless because it has no diff lock option, nor does it have additional tires options, but somehow it can carry long semitrailers?!
In a game that is concentrated around the mud from hell version of original Spintires, this truck has literraly no application, not even as a scout, because there you have multiple choices.
It needs the diff lock and the chain tires back.