None of those options sum up my view. I do care about grain and I do add it into my images. I use ASE for all my colour processing and grain. I don't want it bundled with EOS whatever because I don't use their software as it is crap. I don't want the processing in camera because a) - I shoot RAW so process after anyway and b) Some photos I might want more grain than others. I'd rather start with a clean image and add any effects on after than start with a processed image of any sort. Cameras do not make my choices for me.
There seems to be a presumption here that grain is wonderful and everyone loves it. I don't think that's entirely valid. While some folks like it for artistic expression, I guess, I never wanted it in my B & W. I just shot a couple of B & W rolls recently, one a 100 ISO and one a 50 -- to reduce the grain factor. You'd have to take me out in the middle of the night to get me to put a roll of Tri-x in the camera!
I do agree the typical conversions of digital images from original color to B & W (never tried the B & W function in the camera) are not good. So, like you I'm using Silver Efex and loving it. And when I look at their film emulations, I hate them all.
There is a big difference between noise and grain. Grain can add character to an image. Noise reduces the quality and resolution. Adding grain in many PP softwares is horrible. I hate lightroom grain. Alien skin exposure can add different levels of grain to highlights, midtones and shadows creating a much more pleasing effect.