I spent a few hours checking some threads and articles on the topic in question and I would like confirmation from you: according to the AIM FAA manuals which state:
4-3-6(c)(2)(c) When considering the amount of runway available for use in takeoff or landing performance calculations, the declared distances published for a runway must always be used in lieu of the runway's physical length;
4-3-6(c)(2)(d) An aircraft is not prohibited from operating beyond a declared distance limit during the takeoff, landing, or taxi operation provided the runway surface is appropriately marked as usable runway";
I would easily reckon that if ATC gives the pilot the clearance to line up and wait with backtrack from a certain holding point, then the pilot can at any time choose a shorter distance for takeoff; this is done thanks to his assessment on the runway, lining up on a different point, resulting in a take-off from a non-declared distance (shorter than any intermediate holding point/position)
i.e. -TORA 2000m (published) -intermediate takeoff 1800m (published) -actual length for takeoff being 1700m (not published)
A c150 for example could ask to line up and take off from a position that's some hundreds meters/feet beyond the starting point (reducing the TORA) thanks to its performances...
So the question is 'are published distances such as TORA meant to be used in full or just a reference for pilots to make the assessment on the sufficient distance for take-offs?'
I am in Europe and our legislation follows the dictates of EASA, but I welcome your advice and observations deriving from the FAA regulations