Two tricks I use that may be useful for you:
Add a second launchpad and let half of the factories deliver to one, half to the other. Works great for P1 planets when I do wish to spend less time on them. Downside: takes extra CPU and PG, but for me that’s worth it.
Alphabetical order - when setting up factory planet routes, place all infrastructure first and set the routes from the launchers based on alphabet. For example if I have a factory planet for gel-matrix biopaste with three launchers that respectively take biocells, oxides and superconductors, I make sure that the top launcher takes biocells, the second takes oxides and the third takes superconductors. This makes it really easy for me to remember what goes where without having to look up the routes.