Actually, what I ended up doing was using the nylon screws and washers. The don't seem to bind at all. I am not that worried about stretching as much of the force associated with the string tension is down into the bridge. I'll keep an eye on it, though.
I have gotten things adjusted pretty well (nylon screws, bridge angle relative to body, string height) , and it sounds much better, although certain saddles sound better than others still. Some still have some high frequency resonance or ringing. But...
It turns out that adjusting the string height screws significantly affects the tone, even with very small rotations. Hypothesis is that the tips of the screws are riding in/out if the little tracks that Line6 etched into the bridge plate for the pointed LR Baggs screw tips, for lateral positioning. Anyway, at this point I can get pretty close on the tone by doing very small adjustments of one or both of the height adjustment screws.
I am very interested to see the new version of the bridge and see if they retained the "tracks" etched in the surface of the bridge or not.
As to the question "do the GT saddles sound better than the LR Baggs", the answer is clearly yes for me, but my stock saddles sounded really bad so my comparison may not be valid for you. I will do an A/B comparison when I get the updated bridge from Full Compass.