I think the community would really like to be able to do livery designs on the containers for Sand Patch Grade.
I 100% agree, but this is the wrong place to post this. This is the TS forums, I think you meant to put it in TSW2.
But on the subject of containers, maybe use something that resembles prototypical container companies, kinda like on the freightliner Class 57 wagons - they're not the official names (I'm guessing due to licencing) but to the untrained eye, look almost real.
That would be nice. CSX intermodal containers are prototypical, just not entire trains of them, and it would be nice to have more variety, however it is done.
This is what GTAX, VNHRR, Great Northerner etc have done with their routes, they've used containers with liveries based on real containers, but changed to not be real. The only exception is the EMP container, which is identical to the real life EMP, this may be because Union Pacific own the containers IRL