And would it hold if the average sized adult was to fall against it. I doubt it very much. Takes me all of 5 mins to line up, mark, drill & plug 4 or 5 holes (unless it's porcelain of course!)
Probably a bit late for your screen but these are brilliant... Hanging huge rads on plasterboard was always a challenge until I found these! They also work very well for replacing some toilet seat fixings, unlike normal toggle fixings they are dismantlable... Pricey though so only use them when I really have to. http://www.toggler-uk.com/snaptoggle.html