It seems like buildings that take the ultradense utility cube as fuel should also accept the phantom ultradense constituent (not unlocked yet but the fuel box says it only accepts ultradense utility cube). Then you could set up bulk processing of rare earth metals in ultradense furnace after researching dimensional manipulation. And maybe alternative recipes later with replication gel that take phantom ultradense constituent as catalyst instead. And more replication recipes as late tech. Would allow for massive scaling in combination, and might make it worth the massive trouble of sending constituents all over the factory for parallel production of many different types of recipes even though you would have to somehow collect them all of them for the recipes that only accept the full utility cube.
I can see abstract interrogation tech now, though with Factor Planner I didn't really spoil what happens later but it seemed that phantom ultradense constituent and replication gel aren't as utilized as I thought/hoped they would be.
Reading through the tech tree and the descriptions is pure joy, the techs seem really both useful and hilarious (both because of descriptions and how they affect gameplay with the crazy recipes). The alternative bulk rare earth smelting recipe is also such a good example of why the idea of this mod is equally engaging and just silly fun :)