Originally posted by Flugelbinder I believe the answer to the question is, nope... A zoomed flash will have a much longer reach, not possible with a Flashbender or the like...
That's correct, the answer is "nope".
You want to create a big bright patch on the wall/ceiling in order to create a big (secondary) light source. If the wall/ceiling is not close by, the patch created by the flash will be much bigger than needed and thus also cause less light to arrive at the subject (from the desired location). Hence, it is useful to be able to zoom (as opposed to block), so that the light from the flash is focused to a smaller area and thus creates a smaller, but brighter patch.
If you simply block the light, the patch will also become smaller but will have the same low intensity as without the blocking.
The light "focusing" property of zoom heads is the reason why manufacturers publish the GN at the highest zoom setting. If they published the GN at the 35mm setting, for instance, it wouldn't look nearly as impressive.