I understand what you mean for sure, and you may be right.
The whole idea of doing the tremolo picking thing is to find out which picking motions, grips, angles and anchors work for you, that’s all.
Then you can apply those same techniques to playing more than 1 note on the same string, then progress to playing more notes on different strings.
The picking exercise you are working on, is it on a single string ?
I guess you could say that if you are playing across the strings, then the motions you will use will be different to those you use for tremolo picking on just one string, but that’s really only because you need to make those string changes (the escapes).
The motions you use when picking multiple notes on the same string should be the same as the motions you use for tremolo picking.
This is why the advice is to start with tremolo picking, and just see what works for you and feels comfortable. Then you can move on to trying to play licks on one string and then changing strings (escapes).
I have been going back to try and change my picking motions again, and I have been using tremolo picking WITH string changes to experiment with using different joints, grips, anchoring. I used a metronome to find my top speed at tremolo picking, then kept it running and tremolo picked even or odd notes on each string to see how the string changing works with the motion I was using. May not be a tried and tested method on CtC but I’ve found it helpful. Although, I’m back at square one using the same USX wrist motion I have for 30 years with a weird elbow jerky escape motion for escaping downstrokes. That’s the only thing that works for me it seems. But for you, progressing into the shredding world, there could be multiple motions that work for you on some level.