I found at least one property where the Hilton rate was higher than booking direct with the hotel - unfortunately I can't remember which one as I've been looking at a bunch

One thought that crossed my mind: when IHG partnered with Six Senses, there were some great redemption values to be had. I got Fiji Six Senses at about 1 cent pp which was pretty good. Unfortunately, I had to cancel due to COVID restrictions not being lifted in time. I re-booked for a year later, but by then redemption rates had increased so I only got about 0.7 cents pp. I think it has fallen even more since. I suspect the same will happen here as SLH gets better integrated with the Hilton program.