Yes the wood will take on some moisture. The cherry that I had at sub 3% and well.as the oak all took on some moisture. When you take apart the kiln you will be removing the wood from its arid environment to your local environment. we get alot of humidity here so the wood did go up.. but not alot. when I checked the splits they went from low single digits to low teens. That being said your not going to have to worry about your wood going to 20%mc.. unless your wood gets wet.. This is what you will need to look out forDoes the wood take on any moisture if you get it down to single digit moisture content? As in the beech that you took to 2% , did it come back up? I'm assuming too low of mc causes wood to burn faster and affects overnight burns?
Your wood in the single digits will catch quicker, it will burn hotter. It will catch quicker because is super dry. It will burn hotter because the wood has less moisture in it. Moisture in the wood cools the fire process. so if your burning wood at 3% and im burning wood at 20% I will have 17% more moisture by weight.. This is why wet wood is hard to catch and smolder. You will just need to keep an eye no the stove as it may get up to temp quicker.... as for burn time I did not notice the lenth of my overnight change.. I still got quality overnight burns..