Thank you! I've tried a bit, but think I was stumbling across unrelated stupidity on my end. The instanceFini which I completely forgot about threw me for a loop for some time. Got it to work-ish, but not production ready for the test I had in mind.
I've been working with making a LED wall specific node set. One part of this I'm trying out is splitting images, crop them and shove them into layers. As crop isn't a native function, but a shader, I've been trying to merge a couple nodes into one. However, by making a function to crop rather than stuffing the shader part in the main node, I've stumbled across something I have dreaded a bit to get to (understand); the node instance data/event thingy.
I would guess it's slower since you're running multiple nodes/processes serially-but-also-paralell-kinda(?) inside a Process List node. In comparison the calculate list would only run through its calculations without having to consider the other nodes and synchronisation before outputting a value to the item.
If it is an issue with one of the calculations taking a longer time than the rest, you can possibly try to remove one of the calculations at a time. If it improves efficiency you can take the worst culprit and split it to see if it helps.
Addressing value.x/y/z/w inside both the calculate and the calculate list node would be great though.