Yup, that’s a great suggestion!
To be colorblind proof and limit visual noise on the compass, probably better to place the 1, 2, 3 waypoint numbers within the yellow dots, and use a start/end icon instead of a S/E letter close to the blue and green dots (and reserve them for South and East).
A bit like what is proposed with the dive planner icons (see user guide §10.2 p. 60, for instance the surface icon to represent the end).