Bumping below as no response from any hard deck advocates:

1) Lets define a typical contest area as a circle with a radius of 75 miles from the contest site. Lets assume this is Elmira. In this area the valley floors likely vary +/- 300ft and often that much within 10 miles of each other. Creating an SUA file to account for this would be nearly impossible.

2) This is one more thing that will cause people to be staring in the cockpit instead of outside. Spending time looking at computers WILL lead to not spending time looking at potential landing sites. This WILL lead to accidents that would otherwise not occur. The question is will the hard deck prevent more accidents than it will cause. This is a question that would likely take 10 years of data to analyze. In the meantime the rule may cause more deaths than it prevents.

3) The rule will penalize perfectly safe flying. I remember a 60 mile glide in dead air coming back to Mifflin while in the back seat of KS. Detoured to Jacks a few miles west of the airport and arrived about half way up the ridge (250ft+/-). Minimum sink speed and on top of the ridge in 30 seconds, home for the day win. If the SUA had a 300ft hard deck in the valley we would have crossed under it on the way to the ridge save. Result - landout.