No you don't ever have to move in an arc. Standard movement forces you into it in some situations, but it is by no means necessary in any case. I'll say it again, just move in a straight line to where you need to be. That's it. I also never once said you only have to stay at the transition to be able to do positionals. If you think I did then you need a lesson in reading comprehension.
I'm ignoring your bad attempts at humble bragging about the skill needed to use legacy because it's just a humble brag and either Legacy is easier or harder, not both.