I use an equilibrium brine for brisket that includes instacure#1 & a side effect is the smoke ring. I use Martin's formula (diggingdogfarm) to determine quantity. It can be found under the brine section in a post by DivotMaker about equilibrium brined. I did one last weekend & the ring penetrated about 2/3 of the meat. However, I don't worry about the ring, only the taste.
Didn't know you added the Instacure to your brine, Walt! Brings a little tear to my eye when I see someone paying attention!
...EQ brine and all!! Yep, the curing salt will sure give a faux smoke ring - but you're right, you need to use the calculation so you don't over-do the salt! You just made my night, Walt!