Slow and fast inversions, spiral vs straight inversions, etc were all part of the many things I tried. I also use a section of a film plastic can, length cut just to the remaining space between the top of the reel and the inside surface of the lid to keep the reels from moving around. I've also done many rolls without these spacers, seems slightly less surge with them. Tried pre-filling the tank and dropping in the reels, and vice versa, with and without presoak.
Reels are either Nikkor (original, both 35 and 120) and Hewes for some 120. I've had the Nikkor reels since the late 60's, they've always been my favorite, once if found the best technique to load them. The tanks are Kinderman - I like the flexible lid.
I even got surge with Trix and Rodinal using a reel (120) in an open Kodak 4x5 rubber tank, just lifting and moving every minute by hand - lights off. Still there.
I have considered the long trays mentioned re Robert Adams.
One additional note - I never seemed to notice much of surge effects when printing, but they are really evident when scanning (old negs), which I find interesting. They are much easier to combat in PShop, though.