From some other things I’ve read, specifically for Sous Vide, temperature danger zones are in that 40-140* for longer than four hours. That’s when you can get the bacteria that is mentioned in the articles. If you get past that temp, it begins to pasteurize and kills off bacteria. There’s a specific time that it takes to pasteurize at various temps. For smoking at the colder temps, bacteria risk is same and hence the pink salt.
But I’m not an expert on this, so for the smoked sausage that I made and will make in the future, I’ll use the pink salt for safety precautions. It’s such a little amount compared to the overall meat, it’s just how I’ll go with it.
But if you plan on cooking them immediately at hot temps, like on a grill or boil, those fresh sausage recipes don’t use the pink salt from what I have read. But, it’s not getting the smoke you are wanting. Perhaps liquid smoke helps solve that.
So, perhaps the method you mention using a hotter cook and getting the temp up past the danger zone within the time is fine, but who am I to say it’s ok. But your point on rendering out the fat it also spot on. Fat begins to melt out of the sausage and you get dried out sticks, so the reason for cold smoke or lower temp smoking.
Again, I will not forgo the pink salt for the sausage I make if it’s going to be smoked first. Purely for safety reasons, just don’t want to chance it. I don’t want anyone to read my comments and think I am suggesting to smoke without curing salts.