This isn't an excessive coal build up problem. This is "still in the middle of a burn cycle and need to load for the overnight burn" problem.
This is exactly the problem. Also why you had a BK owner post about it also. When I did it the other night I had to choose from these problems because of it:
1) Let the stove go and wake up at 3am to a cold house because there was not enough of the load left to carry 8-10 hours.
2) Just throw a couple pieces on, which would fire up quickly causing a short burn and waking up to a 60-64* house in the morning and having to do a cold start.
3) Put an actual load on, which with that many coals and 400* would take off sending the stove to 650-750*+. That would be fine if it was 0*, but at 30*+ that would send the house temp to 80-90*.
4) Wait another two hours or so to reload at the proper time and temps. Meaning 2-3 hours less sleep.
5) Cheat. The option I choose. While I'm not a huge fan of the compressed wood blocks I have found some uses for them. One of the things I have learned is they are extremely predictable in small loads in my stove. I raked the coals to the front, piled 4 (3+ pound medium sized blocks) in the very back, one in front of them. Then pushed the coals up to that one and put one on top of the coals. The stove fired the secondaries within 5 minuets, closed the air to 1/8" and went to bed. My tel-tail paper clip on the thermometer said 575* peak stove top. Woke up 8 hours later to the house at 69*, stove at 200*, clean glass, and enough coals to relight easy on the morning. Well worth the $2.99 at TSC for a bail out.
It is just one of the problems you can run into with a stove with plenty of firepower or longer burning. It's a much better problem to have than having to reload the stove in the middle of the night when it is zero outside. Even at zero I can still pull 8-9 hours and keep the house close to 70* when I get up. As long as I have my act together it is usually not a problem. I just got used to the colder temps, got complacent, and didn't think thru what I was doing. Once you get good at learning this style stove they are really great stoves for what the are. By adjusting load sizes, wood, etc. I have burned for 5 weeks straight without using a match.
Now one of the problems I have to contend with is my schedule is quite screwy allot of the time. The wife works a normal job so we are up by 6 am every morning. I have my own business which leads to anything from being home all day to being gone at all different times and for all lengths of time from an hour or two all the way to gone for days. Some times I may have to leave unexpectedly and some times I have a set schedule that could be anything. Basically I am just stuck with what I have to deal with and in reality there is not allot of better answers. To have the best chance I need a stove that can do 10-12 hour burn cycles most of the time which my stove can do now 80% of the time. The only other better option would be 24 hour burn times. The other "better" stoves would be a PH. So far it does not look like it can do 24 hours so it is a 12 hour stove to me most of the time. A smaller BK can do 24 hours, but with my heat requirements and the winters we get here it would only do 24 hour cycles in mild shoulder season putting them back to 12 hour stoves for 80-90% of my heating season. Next a BKK, would do at least 24 hours maybe 30-60% of the season. The only problem with it besides the price tag is I would have to look at it in my living room every day (sorry) and with black glass most of the heating season, which would drive me insane. They release the Sirocco, Chinook, or Ashford 40 or 50 and my wallet is in trouble and I might have to put myself in therapy over the glass. If the Sirocco 30 proves good and can keep the glass clean on a 12+ hour burn and do 24+ on a low burn my wallet is probably in trouble. If Woodstock comes out with a stove as attractive as the PH that can do 24 hours + on a low burn I will have soapstone in my living room. The F5100 I could do but it is going to have to do allot better than 30 hours on a 765,000 btu load or it will flat be too much stove for me. That is 25K btu by the numbers on the bottom end. I can get lower than 25K average now cleanly on a burn cycle and it is almost too much. Someone is going to take my money sometime in the future. Just have no idea who it is yet. Until then I am happy enough with what I have.