Spaz,
I have an X2.5 preamp and an X250.5 identical gain structures, different power. I too usually do not go above about 14 on the scale with my 4.5 vrms xlr input...the default gain setting for the preamps (x1, and x2.5) is the lower of the two. Despite what appears to be your voicing and inconvenience by the seemingly restricted volume range, how does it sound? I find that despite the non full use (ive never had a preamp that i can take past "12") i still get great volume control and do not find it a bother.
How does the piece sound to you coming off (former) tubes?
BTW, Pass will mail you an attenuator kit that you can do yourself, but its fairly major surgery. You have to actually remove the board from the chassis and replace 4 resistors. THe effect is to kick back the apparant vol setting by 4 steps (so 0 would be -4, if it could go there, and 14 would be 10..so on). THis does not change the gain at all, merely the initial voltage division to the input before it gets to the gain stage....
I did get the kit, but did not do this, as actually i'm quite fine with it the way it is...