Adding an acid is indeed the way to brighten a sauce. You could go with vinegar (red wine, sherry, champagne, rice) depending on the ingredients in the sauce. Alternately, a squeeze of lemon is often used. Start with a small amount...you can alays add more.
I would add to cool the stew a bit in the freezing container(s) on the countertop first, then in the fridge for a couple of hours before putting in the freezer. This helps the liquid/gravy not to separate in the freezer.
This sounds similar to something my mother used to cook, she would get oyster blade and put onion and gravy powder on top before wrapping it in tin foil and putting it in the oven.
The result was a tender piece of meat with a thick brown gravy on top, it tended to be more on the salty side due to the use of pure gravy powder, was the meat salty?
I ended up removing the bacon after the slow roast in order to sear the fat cap at the end. It turned out okay. Next time I think I’ll just use the bacon to impart the flavors during the marinading/aging process, and cook it without bacon wrap. I think the crust would come out better that way.
One of the points of the serious eats article is to help you achieve a crust on your roast. It seems to me, that if your roast is wrapped in bacon, your roast will not have a crust, rather, the bacon will be the crusty (possibly burned if you are not careful) part. I think this depends on what you want as the exterior of your roast. If you are going for ...
If they are generally the same shape and size, be sure there is room between them for air to circulate and base your initial cook time on one piece. Of course, time is not a very accurate measure when roasting in an oven. So, your best bet is to use a thermometer to achieve your desired level of doneness.