No Smoke, clean glass, but low stove temps

New burner here, I'm running a 30-nc with 18 feet of insulated chimney which 14 feet of runs in the house. I seem to have pretty good draft, but I have noticed lately my fires are burning cooler than they have the past few months. I have searched and read a ton of threads on here but can't come to a solid conclusion for this question.

I was able to get my secondaries burning pretty good then a fire that would maintain 550+ degrees stove top for a while with the damper 3/4 shut before cooling as everything coaled up. The past few days I can only seem to hold 480-530 and the secondaries never get going nice and strong, if at all, with the damper no more than 1/2 shut. Even worse is with the damper open so much Im cranking through my wood pile. On the flip side my glass stays very clean and when these cooler fires are going, I'm not getting any smoke at all from the chimney.

My concern is I'm burning cold fires and building excessive creosote. I have read a lot here and it sounds like as long as there's no smoke it's a healthy fire, but it just seems odd I'm not getting secondaries the nice hot stove.

My question is, is smoke output and glass cleanliness an ok way to judge how clean I'm burning?

I will have a reading available tomorrow when my moisture meter comes in the mail. I would assume if anything my wood is dryer now because I have started stacking it indoors for a few days before burning, but without a meter it's a total shot in the dark.

Also some of these cooler burns have been with hardwood woodbricks (canwick brand) which I figured would burn like jet fuel.

Alright so an update, you guys were right. I had been getting into some oak and found it was still 30-35% . I have a cord of kiln dried being delivered tomorrow and a sweep coming for Monday. Thanks for everyone's input.

Well that was a swing and a miss, haha. I got my kiln dried load delivered and half of its testing over 30 percent, and burning the same. I'll wait to see what the sweep finds and go from there.

Boy, isn't the first winter burning always the most fun?

Yea, I remind myself daily this isn't something you champion in one winter. I'm gonna ride out this warm winter doing the best I can and look forward to doing it even better in years to come.