I found the article you were probably pointing to, and it confirms what I already knew: color balance is the big issue. That, however, shouldn't matter with a black and white C-41 material. It does look like I need more than the 10:40 I originally calculated (linear vs. curve fit time correction), but it looks like 22 minutes will be a good starting point. Consistency would be an issue with the Minox tank even at 100F, because it takes longer to fill and drain than modern tanks like a Paterson -- and for a 3:45 development time, the time to fill and drain is a significant fraction of the total dev time.