If I understand correctly, you're currently preventing LDS shuffle by having the LDS recipe output "molten LDS", which you then have to solidify into real LDS. I think you should also be able to accomplish the same goal by adding a "molten plastic" recipe, and then changing the LDS recipe to take molten iron/molten copper/molten plastic and output solid LDS. This feels a little less arbitrary than having a "molten LDS"; I don't know if it's a huge improvement, though.

Ah, I bet you can't hack 3 fluids into the foundry though, can you? That's too bad - disregard this, then.

Exactly, the foundry only has 2 fluidboxes, so you can't have 3 fluids in a foundry recipe. The molten plastic route would also require adding more recipes than I would like.

seems like the mod author missed the premise of the mod. Making molten LDS should be a 0.1 second craft as this is "no quality cheesing" not "make LDS require twice as much infrastructure to create." Or just you know, disable quality modules from being allowed in the cast LDS recipe. Should think things through a little more in the future.

"Making molten LDS should be a 0.1 second craft as this is "no quality cheesing" not "make LDS require twice as much infrastructure to create.""
It's unfortunate, but I couldn't find a way to plug LDS shuffling without adding another machine in-between. I'd like to change it if there was a good solution.

"Or just you know, disable quality modules from being allowed in the cast LDS recipe."
That does not solve the issue. Since the issue is that you can use legendary plastic to directly obtain legendary LDS, quality modules have nothing to do with this.