Hey, Tirrin,
I just caught this one right now...nice lookin' brisket!
Your mention of lack of smoke ring brings a couple of possibilities to mind...I'm thinking too high of smoke chamber temps (but, this would have to be in the range of 275*, or more), or the high concentration of sugars applied before the smoke had alot to do with it. I've all but stopped using sugars in my rubs...I use them in marinades at times, or brines for pork/poultry, but tend to avoid it with rubs. Oh, and I don't brine beef, per se, except brine/cure for pastrami, etc. I may be wrong, but I've never had a low & slow cooked cut of beef pork or poultry that had exposed meat (fat trimmed off) not produce a smoke ring.
I'll try to explain some of the science behind it: the smoke ring as we call it, technically isn't from the smoke in specific, but from the burning of fuels (natural gas, propane, charcoal or wood) which create nitrogen dioxide (NO2) in the smoke chamber gases.
The red or pink coloring in meat is from myoglobin, which is an unstable pigment. Myoglobin in beef is a purple/red color, until the meat is cut and the surface is exposed to oxygen, where oxymyoglobin is formed, which becomes a brighter cherry red color. Also, during cooking at high heat, the myoglobin on and under the surface of the meat eventually turns to a gray color. Hence the term unstable pigment.
NO2 is highly water soluable and absorbs into the moist surface of the meat, then reacts with the myoglobin in the meat at lower temperatures, and then forms nitrous acid, which in turn creates a temperature and oxygen stable pigment with the myoglobin. This stable pigment retains it's coloring, for the duration of the cooking process, while the interior meat, having the unstable pigment, begins to turn a greyish color as temperatures reach the well-done range. The stable pigment will continue to retain it's coloring after being refrigerated or frozen, and then, being reheated, hence the term stable pigment.
OK, so where does this all fit into the jig-saw puzzle with your brisket not developing a smoke ring? I would suspect the natural sugars in the honey and the processed sugars in the sauce caused a reduction in the penetration of nitrogen dioxide into the meat's surface by forming a semi-impermeable coating on the meat. This likely sealed the surface well enough to keep it moist during cooking, yet in turn prevented the natural process of the low & slow cooking with smoke in forming that "smoke ring".
I don't recall stumbling upon this particular circumstance before, where a sauce and rub were applied pre-smoke, then more sauce during the smoke, along with little or no smoke ring development, so I felt a little science behind the smoke was in order so you may be able to better understand what may be happening. Also, the development of, or lack of the smoke ring does not necessarily determine the actual smoke flavor intensity or quality. Duration of smoke, intensity of smoke, species of smoke wood(s), smoke chamber temperature, smoke chamber humidity and rate of the flow of gases through the smoke chamber (ventilation), just to mention a few, are all part of the many variables which play a role in the actual quality and quantity of the smoke flavor. Electric smokers have one inherent fault, if you will, regarding the development of smoke ring: they do not burn any fuel, therefore, the smoke ring is produced soley by the smoke wood itself, which drastically limits that characteristic in the finished product.
Oh, a couple other things which hinder development of a smoke ring: higher temp cooking, fat on the meat, and skin on poultry.
Don't sweat the smoke ring, though...as I said, smoke ring is really just for looks...cool to see when you can make it happen, but it doesn't make the meat taste any better. So, if you like how you just made this brisket, and your family and/or guests liked it as well, stay with it. You can do a bit of tweeking here and there, but, a good rule to follow is this: don't fix it if it ain't broke...
I'm a major tinkerer, myself, so, I'm constantly breaking that rule...LOL!
Keep on smokin', Tirrin!
Eric