As for the IP around lego bricks, an instruction set would be copyrightable, the brick system is patentable (but the patents on most of the bricks would be expi

As for the IP around lego bricks, an instruction set would be copyrightable, the brick system is patentable (but the patents on most of the bricks would be expired now which is why there are generic brick sets available), and they can do a trademark that would provide limited protection, but mostly for the brand, not for the bricks themselves (I remember being at the Lakland workshop back in the 90s and they were talking about how the Fender lawyers came and told them how they needed to redesign their headstock as to not violate Fender’s trademarks/design patents on the headstock shape, and there would be some similar protection potentially available to Lego, but again, the existence of generic bricks tells me that it doesn’t apply to the bricks). So the bottom line is that Lego cannot keep you from publishing plans and parts lists for your own Lego sets. Heck, you could even, if you were sufficiently funded, manufacture the set yourself. You just couldn’t use the Lego brandname at all.