Another example of this sort of interface is office phones. When someone knows their phone well, they can speed through a hold, page to another desk, then transer to them, without even looking at the keypad.
I have a feeling that sort of "trainable speed" is a feature of interfaces that treat the thing they manage like a physicial "thing" you're rolling thru a process. (instead of a feature of textmode interfaces) Rather than having to get to a menu for outside lines in some abstract window, there's just actual physicial buttons to mash. You get this feeling that you're juggling a call between your fingers because every press you do is doing a "thing", not just opening a menu. There's real physicality to that process that my monkey brain can learn no problem.
I don't have any experience operating a terminal based PoS, but from what I know, they tend to also have the same sort of "juggling" actions, like SALE, DISCOUNT, VOID etc. I have to imagine using them feels like juggling the current item you're looking at thru a few different buttons.
I have a feeling that sort of "trainable speed" is a feature of interfaces that treat the thing they manage like a physicial "thing" you're rolling thru a process. (instead of a feature of textmode interfaces) Rather than having to get to a menu for outside lines in some abstract window, there's just actual physicial buttons to mash. You get this feeling that you're juggling a call between your fingers because every press you do is doing a "thing", not just opening a menu. There's real physicality to that process that my monkey brain can learn no problem.
I don't have any experience operating a terminal based PoS, but from what I know, they tend to also have the same sort of "juggling" actions, like SALE, DISCOUNT, VOID etc. I have to imagine using them feels like juggling the current item you're looking at thru a few different buttons.