Hmm ... I don't recall that I said that the lower the Q1 the "better" jitter becomes. Besides that it isn't proved by all people.
I did say though, that as far as I can recognize, the soundcard's buffer should be as low as possible. So maybe you have that in mind ?
The upper range of Q1 as well as the lower range has its limits. These limits are actually there right now, although I must honestly say that the upper limit is related to somethings that is factullay unknown (by me), but together with that it is my reasoning that it shouldn't matter anymore above the upper limit from right now. One exception exists to this : that one exact Q1 number your DAC may respond upon for upper limits. This though, will always be too critical and too much depending on the performance of the PC itself. Too keep it simple : the DAC's buffer will underrun at this one special number.
Ok, despite all I still could increase the upper limit, just as I could increase the lower limit. The point is though, that increasing the upper limit goes along with a "resolution" that never suffices. Think of an logarithmic scale, and one step above the current limit would be a double sized one. What I said above still counts though, and it implies a necessary scale of something like 700 steps above the current 30, to reach 31. Relate this to the current 35 steps, and you'll see the unuseable thing coming from it.
Much more easy, would be a checkbox to double the resolution within one chosen number. Thus, when you have chosen e.g. 28, you then can choose from 27.5 to 28.5 in a 35 step resolution.
I always intended to make this, but it never came to that because other improvements caused more change to SQ. As a matter of fact, it stopped me from playing with Q1, while actually that should be done at each version that claims improvement on SQ. But as you will know now, it just takes too much time to do that after each upgrade (for me anyway !).
But I keep it in mind. It has been quite some time that someone mentioned explicit testing about the Q1 anyway.
And mind you, this will make me to try 28. One never knows ...
Thanks.