Youre running too much sag, unless you are setting the bike up for comfort as opposed to speed. Although I do drop to 25 percent sag for slow tight and twisty technical trails.
Have to run them stiff to keep them propped up which usually means i never get more than 75% travel out of them. I wondered therefore as the Devilles are alleged to sit higher in the travel and not prone to diving would they run similar my current setup with the exception of giving up a bit more travel when required.
Are you running floats? If so isn't the spring rate progressive and when you set up for the correct beginning and middle stroke support the ending stroke becomes to hard because of the progressiveness of air springs. What you need is a nice properly setup linear coil spring (U-turn lyriks are not, 36's and the now discontinued coil Lyrik RC2DH are). MXers tend to stay away from progressive springs of any sort.
I should imagine LoCo is the guy to talk to.