I did that run for a while. The issue I have is that the variability in stock at the station means you either end up sitting in the station for a tick (or two), or you fly the route half-empty sometimes. What I did for that was to make it kind of a loop. From the Lave cluster I hit Any, Na Arouca, Chi Eridani, Kappa Fornacis before the witchhaul/fujin/39 tauri cluster. I then go to Tanmark, tarach tor, utgaroar (all rather close to witchhaul), then kachirigin, kamorin, vanayequi, heike, helvetitj, before heading back to orerre.
With 88-ton capacity Asp I spend most of my time near full. I try to sell when I hit between 160-180 LY, but sometimes end up selling early (120LY) to make space. Sometimes I'll be pretty light for part of the trip, but having more stations smooths out the peaks and valleys.
The downside is that you're never at the end of your run. You've always got some rares that are close to home, so if you decide you want to go bounty hunt (or whatever) for a while, you're either doing it with some rares in the hold, you're selling at a lower price, or you take a 160ly detour to sell. I really wish I could switch ships with cargo in the hold; I'd love to be able to break up the loop by storing the asp and switching to another ship to do some shooting before continuing on with trading. Hopefully that's a feature we'll get.
