Other brands, good ones with similarly smart employees, do not instruct the operator to run wide open for 20-30 minutes after cat engagement. Rather, they say to immediately begin turning the air down after cat engagement. I think it’s worth getting the load charred and the system thoroughly warmed up at the beginning of each load. It should benefit your efficiency for the rest of the long and low burn.This morning when I reloaded I only left it on high until the cat was at 3:00 and then turned the thermostat down to about 5:00. With it at 5 I was able to hold flames for over 20 minutes without the cat going beyond the active zone very far which got all the wood charred I then turned it down to 3:30 and it's heating nicely. Seems to be a trial and error situation but I'm getting it dialed in. I'm sure it will all change when I get a row or two into the shed and hit some bigger splits and some birch.
Good luck. It’s hard to really mess this thing up if you shut the door and get the bypass closed as soon as the cat meter reads active.