Some comments, if I may.
The original 50ft screen goes back to some US military demonstrations (Curtiss, as I recall) a very, very long time ago .. The demonstrations were at a military parade ground (I didn't get the specific location in the original tale from an ancient Aeronautics Branch/CAB engineer) but the area was surrounded by trees of around 50ft height. As with a lot of initial civil rules, TLAR ruled much of the decisions in those days.
The heavy 35ft screen will date to the ICAO report on performance in the 50s - I would have to dig it out to locate a specific reference - there was a number of changes introduced around that time to accommodate the piston to jet transition period. 50ft screen, though, continues for the lightie brigade.
So far as compliance with things might be concerned, I presume that most jurisdictions will have a requirement similar to Australia's CAR (1988) 138 which says that a pilot must comply with the flight manual requirements. While I have no legal competence, that probably means at law that, if the flight manual says you require a certain TOD, then you need to operate from strips with not less than that distance on the day. How the pilot actually should manipulate the aircraft may have some guidance in the flight manual but, I suspect, if the pilot chooses to fly over the far fence at a low height (eg in a light twin to get some extra speed for the possibility of a failure) then that might be subject to post mishap discussion both at law and with the insurance company ?
In respect of the OP's question, I doubt that there would ever be any sort of rule which might seek to impose a requirement to cross the end at 50ft - in general, we would be significantly above that level for most runways, depending on what might be built into the flight manual performance data for a particular jurisdiction NAA.
Be wary of quoting TORR/TORA data as that really only is used for heavy aircraft performance work. TODR/TODA is the more relevant metric for lighties.