I don't think he is overcharging. But when system is undersized - seems to be the case - something needs to be sacrificed. Doing 2 stages, boost charge most of the time, is not optimal for batteries, but this is a lesser evil than not getting them to 90-95% at all. AH number for the day does tend to slip lower when Float stage is lingering for more than 3 hours, - though this wouldn't matter with more solar. The batteries would then get over 95% and the difference btw all-time boost and more optimal mode would've been 1 or 2%, ex. 98% vs 97%.
I didn't read the whole thread - 66 pages is when topics becomes either dated or weer sideways, so can't say about this controller.