I am not sure I totally understand what you are asking. Do you mean that you want the trackponts in the stabilise node to move 1.2 times the speed of the trackpoints in your tracker. Have you tried the following?
Stabilize = Stabilize(0, 1, 0, "1 point", Tracker.track1X*1.2,
Tracker.track1Y*1.2, 1, 1, 2*width/3, height/3, 0, 0, 2*width/3,
2*height/3, width/3, 2*height/3, "default", xFilter, "trsx",
0, 0.5, 0, 1, 1, 0, 0.9375, "v2.0", 1, "1/64", "luminance",
0.3, 0.59, 0.11, 0.75, "use start frame", 0.5, "stop", 0,
0, 25, "track1", 360-height/25, 360+height/25, 288-height/25,
288+height/25, 360-height/15, 360+height/15, 288-height/15,
288+height/15, "track2", 2*width/3-height/30, 2*width/3+height/30,
height/3-height/30, height/3+height/30, 2*width/3-height/15,
2*width/3+height/15, height/3-height/15, height/3+height/15,
"track3", 2*width/3-height/30, 2*width/3+height/30, 2*height/3-height/30,
2*height/3+height/30, 2*width/3-height/15, 2*width/3+height/15,
2*height/3-height/15, 2*height/3+height/15, "track4", width/3-height/30,
width/3+height/30, 2*height/3-height/30, 2*height/3+height/30,
width/3-height/15, width/3+height/15, 2*height/3-height/15,
2*height/3+height/15);
Tracker = Tracker(0, "1", "1/64", "luminance", 0.75, "use start frame",
0.5, "stop", 1, 1, "v2.0", 0.3, 0.59, 0.11, 0, 10, "track1",
width/2, height/2, 1, width/2-height/30, width/2+height/30,
height/2-height/30, height/2+height/30, width/2-height/15,
width/2+height/15, height/2-height/15, height/2+height/15,
width/2, height/2, 1, 1);