I guess they should have stated that it was a Resin 3D Print. N scale version is the same but with a few of the parts injection molded.
But it really shouldn't change much with assembly. Just gotta be more careful handling it and make sure you assemble with non solvent adhesive.
The reality is, you're right. I wasn't so concerned about it being a resin 3D print as I was getting hung up on their advertising it "cast in color"...and then just leaving it with the support material attached. (first impression was that seemed a little tacky, and lazy)
So it was a bit of an expectations thing combined with a bit of a first impressions thing. The truth is, even if it was "cast in color", it would have eventually been painted. The support material isn't unlike the sprues that injection molded kits utilize, and if that has to happen to keep interesting stuff coming in Z then so be it. (I forget sometimes that being in Z is sort of like being in 90's N-scale....still the redheaded stepchildren--and the smallest market share--of the hobby)
I still think it could have used a communication...."hey, we're changing this up a bit." And at roughly $12 street price after counting out the typical cost of the MTL weathered gons, I think they could have removed them from the support material, but again--I'll deal.