It would seem you take all the correct precautions and dont burn wet wood for long periods. Your temps are fine! If it is working don't change a thing, people were just injecting their opinion as was I. I should have mentioned my brother also occasionally put some kind of powdered "chimney sweep" in his boiler. I can't say how effective this is. He figures it doesn't hurt anything.
Old timers I grew up with advocated burning constantly to keep the flue temp up, burn hot to minimize creosote and keep the flue hot and draft high, and don't ever smolder a fire for long periods. If you need a little heat, burn a small fire hot and let it go out. Many here do not subscribe to my theories so you will hear other opinions. These old timers had just single brick chimneys with wood built right up against them. Seems most of the fires were people that didnt follow the rules. My parents house is so old it had trees for studs between the beams, vertical boards on purlins made of flattened trees on the roof, and birch bark for flashing around the ancient windows. It had one central chimney with three thimbles, two of them were in horizontal "flues" made of brick.
Seen it in many old houses in Maine and they are still standing. Until someone comes along and smolders a fire for weeks. Epic chimney fires.
Another opinion some don't like, masonry is fine for coal, it sucks for wood. Especially if it is on the outside of the house. I had one I built with a liner 23 years ago and even though I burned it hot, ruining a Vermont Casting Vigilant twice, I still had chimney fires. It was inside all the way to the peak and would be hot to touch, but the creosote would form just as soon as it exited the roof. Never had another chimney fire I worried about after I installed the wood boiler with the insulated metal chimney.
Just pay attention and follow your instincts.