First, I'm not currently using Adobe RGB (1998) D65 WP 2.2 Gamma in any of my workflow (as far as I know). It's on my computer, put there either by MS, HP, or one of the image editing/manipulation programs I have or have had.
I read the CinC article a year or two ago, and am familiar with it. Also the Color-Image article, and other similar articles (DigitalDog, etc). (I don't use sRGB for printing because I don't like the way reds and purplish-blues look. Depending on the image, I can often see the difference on screen.) I'm certain I'm doing things wrong, except I like how my prints turn out. (I've experimented with different printer evaluation images, using different paper profiles combined with different printer media profiles. Sometimes one has to really look to see any differences.)
My question probably should have been: why is Topaz using Adobe98.icc instead of one of the others already installed on my computer? If it's better, why wouldn't I want to use in the rest of my workflow?
iTunes, Qimage Ultimate, Corel, Canon (printer and scanner), Afinity Photo, and more, use AdobeRGB 1998.icc.
There's only one way for me to find out, and that would be to do what others besides you have told me not to do: test Adobe98.icc by putting it in my System32\etc directory and run a few more tests. (I've done this a few times before, I think I tested a linear ProPhoto icc or something.)
If I learn anything useful, I'll report back.