You're doing it right. Honing like that is really the best way to go about keeping any cutting implement in good working order. :thumbup:
It's like the old saying, "an ounce of prevention is worth a pound of cure". A few minutes spent honing or stropping at the end of a long workday is much easier than 30 minute's actual sharpening at the end of a long week. Some butchers and chefs steel their blades several times throughout a shift to maintain their edges, rather than ever letting them get really dull. I feel strongly that most people who find sharpening difficult simply wait too long, until the knife is very dull and requires a lot of stock-removal to bring it back to good edge geometry.
However, for the purposes of this challenge, you may find it interesting to not hone your 15 at all for the last week. Then for your last test, cut up a whole bunch of cardboard. Just to see how dull it really gets, in what way does it get dull (micro-chipping, rolling, flat-spots from wear, a combination of all three?) and how difficult it is to go back to a coarser stone and actually sharpen it. That will give you a real good idea of how the steel/HT holds up, what you need to watch for, and therefore how often you need to put a little preventive maintenance into it.
