Ex Douglas Driver,
My thoughts (and only mine at this stage) on the 60m is that it's the standard length of a clearway, and nothing more.
Standard stopway (RESA) .. clearway varies according to the airport and runway.
I want (and fully expect) a fool-proof procedure ...
Probably no such thing (due to most of us being fools from time to time) but the goal is admirable. Likewise, complete safety doesn't exist .. only levels of hazard and periods of exposure.
However .. a good attitude makes a good place to start ..