I don't think altering the tracking is going to affect the handling downhill a lot.
What it will do if you get it wrong is scrub out one front tyre.
If it's spot on, there will be no difference in wear between your two front tyres after a 1,000 miles.
I'm over 8k mile with no difference in wear between the front tyres on my ICE Sprint.
The one time I knocked the tracking out of line by bending the frame, I only got a few hundred miles out of one front tyre before it was worn out.
Luck ...........
