I haven't tested this mod at all yet. I see it now and it made me wonder how this mod works with the Matter mechanics of Krastorio 2. In case you're unfamiliar:

Matter is an end-game resource in Krastorio 2 wherein all base ingredients can be turned into a liquid called Matter. This Matter can then be solidified back into any of the other base ingredients "lossless" (i.e. 1 copper ore -> matter -> 1 copper ore, though different base resources have different matter values, so it may take 2 stone to make 1 copper ore, and 1 copper ore to make 2 stone).

Now here's what I mean in relevance to your mod: Matter can be solidified into Matter cubes. These cubes can be used to make slightly more advanced intermediary products, such as Copper Plates. Using these slightly more advanced methods, you consume something called Matter Stabilizers (I think it's 98% efficiency, so for 100 advanced intermediary products, you lose/consume 1 Matter Stabilizer on average)

I am assuming using Pneumatic Transport in K2, you can completely bypass having to use matter cubes at all as even matter cubes would be liquid, and you'd just use the liquid matter to make base resources and then use the liquid version of base resources into liquid versions of the advanced resources.

I don't know if you care at all, but I thought this train of thought could pique your interest. It's one of those "Now you're thinking with portals!" moments.

The way the liquifaction works here is that every (or at least - nearly every) item in game is processed to create a 'liquid' variant with 2 recipes added for each that convert between solid and liquids. The liquid variants of the items cant be used for anything except for converting back to solids (since this mod is the one that made the liquids and no other mod adds recipes using them).

This means that even mods that potentially have an item like 'matter cube' that you make from liquid 'matter', this mod would just add another fluid called 'fluidized matter cube' that you would use to 'pipe' the matter cubes between areas.

You could potentially create a compatibility mod that requires krastorio 2 & pneumatic transport that would replace either the fluidized matter cube or matter with the other in order to allow for such shenanigans, but thats something that would be done on a case-by-case basis - not something that would work with every mod that includes a liquid variant of a solid item.