In general, most of my students have more problem not bobbing when they move than bobbing. The issue is can they control their movements while moving? I train people to improve their weaknesses. Direct movement improves speed and momentum on impact, making it a better movement from point A to point B. If you go up first, just so you can go down, you are wasting energy and time. Unnecessary movements certainly make a person easier to read.
I, in fact, have met a person that could break down all of the applications of the forms you mention. I forget his name, but it was back in the 80's and he had to do a great deal of research (in original countries and original languages). He had over 10 applications for each movement though. Whether or not they were actually 'original purpose' is impossible to know without talking to people that are dead. I can't do that, nor can he. We are left to figure those out for ourselves. Older, wiser martial artists would have said, if you don't know, you haven't done it enough. Were they right or just full of B.S.? I guess we all have to decide for ourselves.