Then I started wondering why not just keep soft-proofing on all the time, since I only print on one paper? Is there a reason not to? I'm never trying to color match, just to get a print that looks good within the limits of looking natural.
The limiting factor is that for your master RGB image you wish to keep long term, you don't want to be influenced and any one media and printer, do you? While you are only using 1 paper and printer now, you will prolly change printers at some point. If all your images have been adjusted to only look good when printed to your current printer it will be a limiting factor in the future.