Tangent has been awfully quiet since the Bethlehem Quad release. I’ve asked them if they planned to do L&N like they did in HO. They said they do plan another run, but that’s been some time ago now. Maybe they are tooling up a correct Eastern version? 
Man, I completely forgot that Tangent was in N. They announced right as I officially bailed on N around 2018. I even talked to them at the NTS in KC, lamenting that the UP quad was something I'd clamored for, and was adding to the growing list of N items that got announced right as I was heading out the door. (alongside the Carbon Black hoppers, among others)
I need to research, I don't think the train I modeled before (as 2001 BNSF with UP trackage rights) existed as a unit-train in 1989, but the coal likely came through as part of a trackage rights manifest train so having a few of both Tangent and Trainworx quads would likely pass muster if not the entire unit train.
Back to the topic at hand of BN Triples, I'll defer to my previous proclamation: "Man, it would really be nice to get a good-fidelity BN triple hopper in N."