An update on this: I had thoroughly cleaned the MAK on the weekend, top to bottom. Today, I took the FZ covers off, loaded up with 100% oak pellets and timed how long it took the PB to register 450. Started the MAK at 10:15 AM exactly - I did not "prime" the firepot. Outside temp about 68*, light wind. It took 31 minutes until the PB beeped that it had hit 450. So, 30 minutes from scratch to get to 450. I would chalk my first attempt up to lower BTU pellets - 100% oak did the trick. Since we're not hickory fans, looks like pure, 100% oak is our "go to" for grilling.
Thanks all.