Johnsonville were my favorite brats for a very long time too, then I found a butcher close by that made some that are out of this world! I also noticed that his casings were open at the ends and they never split open.
I still get Johnsonville brats on occasion, but if budget allows I go with the ones from the butcher.
I am thinking YT is having a casing problem, the casing is weak and can't stand up to the internal expansion. Also in my experience the best ones split a little as they cook letting some juice out but not all of it so they don't dry out.
If I do have one that doesn't split open or let some of the fat out as it cooks, I will poke it with a fork to encourage it.
Again, I don't want all of the fat out, just some so it doesn't threaten to explode on me LOL.
And yea, watch that first bite LOL.