The rule book calls for a 5 foot radius corner but some years back Bob Hunt (I think it was) did some testing and measuring and found that the more typical corner was more like an 18 to 20 foot radius. He then went out of his way to develop a truly silly looking control line stunt model which was light enough and had enough wing area to actually do something really close to a 5 foot radius corner. Guess what.... The judges all hated it. It was too abrupt. Mind you those same judges had been conditioned by many years of looking at more traditional models.

Anyhow, back to the topic at hand.....

As I recall the Somthin' Extra has a constant chord and constant thickness wing with tapered full span ailerons. And the amount of taper isn't all that much. So really while techincally it's not a constant chord I suspect you'd really have to be fussy to find it truly behaving like a tapered wing. Which is very likely why it is so successful a design. The reason that the webbing isn't tapered in width is because the main portion of the wing is simply a constant chord and thickness.