In my one experience working with a keeper I did not get stung, but another guy on the crew did three times. He was running around and making a lot of noise like a little girl. The keeper had a nifty tool that was basically a vacuum hooked to a wood box, but we couldn't get our power source to work so he extracted them the old fashioned way by hand with a brush and smoke. He said that if he could have used the vacuum, they wouldn't have gotten agitated at all. Their hive was like the one you described. It was in the trunk of an old Black Cherry, about 5 feet off the ground. I felled the shank, put on an extra keeper's suit and started cutting the log where the keeper told me to. I did a lot of cutting on that log and the bees didn't seem to care about it at all. They didn't get agitated until we started really getting into the hive. Overall though, it was a pretty cool experience and I was happy to save them. It did make the job take much longer than normal, but I was on city time for that one.