Hi @Wolfgang !
Thank you for also filling in, much appreciated 
Dan Margulis over at LEDET and Modern Color Theory is also a great resource, he wrote 4-5 books about LAB, then he also made some videos over at those popular photoshop training sites. Still much valued today.
Anyway, I have to make you notice this requirement from my fellow colleagues and others in the industry that this is needed so that we can do colors by the numbers easily. They all like the app and what it brings otherwise. I think you have a great potential here to get more sales when adding this simple readout (simple, as if I know 
). I also think it would benefit all users to have option to make a readout stick on screen on a certain point while editing - dynamically changing as you change the curve or controls, but that’s another tool. This one will simply bring in more customers first day it’s added and I could potentially release myself from Adobes claws 
Thank you for considering, and I’m thankful for this great app. I use it daily on my personal stuff.
Aleksander