Also, there's nothing wrong with the hood. It's optimized for the lens. If you don't like it, don't use it. If you don't use it, just remember - you're not getting as much as you could.
+1
why would anyone cut a hood down? if the standard hood does not show on a FF @70mm the your not going to want any smaller.
it goes to show how ineffectual some of these hoods really are. Canons 70-300 IS hood that they charge 40 quid for is little better than pointless
I would like to see more lenses have either reverse zoom and a fixed hood like the 24-70L or extending hoods . The ring extension for APS-C that sigma seem to be shipping with some of their lenses is a good start.
as you could. 
is little better than pointless