Running the spots with the HID Low and High beams is like putting a Black Cat firecracker in the same hole as a stick of dynamite, because more is better.
Bad analogy I know, but you get the point. The HID upgrade effectively converts our spots into marker lights. If I could get them to blink, I'd use them for turn signals and remove the oem turn signals.
Just thought of something. Perhaps we're going at this all wrong trying to match bulb output colors to find some palatable appearance between the new HID and the old spots.
We know the yellow looks harsh in comparison. Rather than adjusting toward the HID, however, perhaps there is simply some complementary option available. Have seen colored bulbs of many type availalble before. Will have to do a little homework and see if specialty colored variants of 881s are availalbe. If so moving completely away from the HID look and toward something that complements the remainder of the bike might be an option.
As you've said, with the HID in place the spotlights really do become ancillary at best. We're just not gaining anything significant with them. So might as well look for dress up options for them.