Isn't that ''combine rotations' block a matrix multiply function?
So maybe if you feed the custom vectors to a 2nd 'make rotation' block, remove the dot products and feed it directly to the 'b' input of 'combine rotations' block while the original ldraw values go to 'a' like before.
So maybe if you feed the custom vectors to a 2nd 'make rotation' block, remove the dot products and feed it directly to the 'b' input of 'combine rotations' block while the original ldraw values go to 'a' like before.