I believe source 2 is correct---because the 15' scren height is for when TODA limits TO on the wet RWY---but [from my rules FAR 135]
on must pass all at least 35' vertically and at least 200' horizontally--with in arpt boundaries and at least 300' horizontally outside---and then maintain a specified gradient above the obstacle plane---which is reduced by a certain margin [or increased--I guess it depends on the point of view
]---since obstacle clearance requirements must be fulfilled in all cases--- if obstacles were limiting then deference has to be made to that and I never seen an AC or such that contravenes that---I'm not a perf expert but that's my take---if I'm not correct---I'm sure I'll find out soon
PA