I use LR for the vast majority of my editing. However, as you wrote, there is no option to "preserve RGB numbers" in that soft proofing flow, which I understand to mean that there is not any way to really show what printing without color management through QTR will look like. Is that correct, and does this render this flow in effect fairly useless?
In terms of photoshop editing, it looks like I indeed can use the QTR default profiles but "preserve RGB numbers" is only available for the RGB profiles. Given this, what is the scenario when the gray profiles are used? Also: I see a big difference when using "simulate paper color". Is that typically the most faithful approach?