Trap speed will increase slightly as your 60' increases, however in finx's car this is a virtual non issue, it's so top end limited that the difference is minimal.
Regarding your issues ted, I suspect the good result is due to the extremely wide and flat torque curve a well tuned CT9 on a 5e has and there's absolutely no wheelspin beyond the very first second or so of the launch. If you have high power, you can wheelspin the length of the track, trap at 120 mph and still run a high 14. Strap on some drag radials and try again, it might help with your ET's.
The discussion around .1 off the 60' meaning .3 off the ET is valid for RWD cars, less so for front wheel drives, in my experience it's more like 1:2 ratio for some reason.