Noticed that the example files for making nodes now have changed since I got started with it. Without the reliance on .pro files for QT-creator, it is now even easier to get started - and you don't have to deal with the whole QT-creator licensing thing.
Install CMake, Download Visual studio code (MS but open... or something like that), install CMake for VSCode and CMakeTools inside VSCode*, open the example folder and you should be set! :)
*you might have to enter the path to CMake in the VSCode config
The approach hinges on user philosophy though. I'm all for less specific-task nodes, and building subcompositions. Not everyone agrees with that though.
Ah! Maybe it just me zoning out a bit. I was trying to get the values from a X/Y position within a layer. Thought I had done it with that node before, but maybe I misremembered :)