seems like you feel “fold” as a limitation, but let me explain in a better way;
as this is not a complex process and is just a different option/view, it can be activated with a click and disabled with a click instantly as you can see at the top of the post in the gif, and of course you can add those notes outside the scales when its need it… fold definitely is not a limitation, fold is friendly, I know what highlight is, because I used in the past with other software which have this option, but when Ableton appeared with this fold option, in the beginning I didn’t understanding, was like an alien, but once I was able to understand the possibilities, for me this was like bring highlight notes to the next level, the evolution. But of course could be nice to have both options… I don’t think highlights and fold be a complex task for a developers like the ones on Steinberg…