Good Evening, Ben,
I just pick up the drum at regular intervals and reverse it on the motor base. I suspect that, for most film/developer combinations, it probably matters very little or not at all whether manual reversal is done. For times in the 10 minute range or longer, I'll do the first couple of reversals at 30-second intervals, then just once a minute after that. (I do use pre-soak.) Manual reversal a good way to reduce the boredom even if it's not really necessary.
I occasionally make a contact sheet (8 x 10 or 8 1/2 x 11) in the drum rather than preparing full trays of chemicals. For 8 x 10, I use the two separators at the "bottom" positions and omit the third one. For 8 1/2 x 11 paper, I don't use any of the separators. The same approach should be fine for film.
Since the only film I do in the drum is 4 x 5 B & W, the cost of chemicals is fairly insignificant, so I don't try to get by with the smallest amount possible. For most film, I'll use at least 10 or 12 oz. of developer. For the other chemicals, I use at least that much, but I'm only concerned about not using so much that some spills out during the rotation.
Konical