I really like the idea that i can combine 3 heightmaps toghether, and process all of them at one node - it is good optimization for LocalSpace stuff that i’m working on
But i’m curious, is this is a maximum limit? I would very love the ability to combine 4,5,6,7,8,9,10…9999 of them and process at ones
Is such option exists in WM or no? 
In this specific instance, the Channel Splitter and Channel Combiner are designed as a method for interacting with the red, green, and blue channels of a color image separately, not necessarily to be used on height data. That’ll be the reason you’re only able to process 3 at a time (and also, specifically 3, if any of the channels are missing inputs, the Channel Combiner will fail to build).
Unfortunately, I don’t think there is currently a method of adapting that workflow to work in anything other that groups of three, just due to the nature of the data type it is expecting. Nor do I think there would be any practical method of implementing something like that, without defining some new image type with a dynamic number of channels.
