one of them is about custom Lego parts for MOC train builders that use this site to build trains and plan ahead before getting the parts, and most lego train models use couples and gear valve bars to make their train models look more realistic and neat.
site examples: https://brickmodelrailroader.shop/products/743s-coupler-pack or https://trainedbricks.square.site/shop/valve-gear-bars/3?page=1&limit=60&sort_by=category_order&sort_order=asc

for the animater in workshop, I think it should be easier to animate by being able to set keyframes like https://clara.io/ but I like to see what exact part I'm animating and how it would rotate, move, and pivot. also, there is more to this but I can't put it into words.