I doubt if the idea will work at all. The principle of dedoming a LED is not about allowing more lights to scatter sideways, if this is the case then why dedomed LED would work as well in an aspherical setup?
Dedoming LED is to increase luminance at the die by reflecting the photons back to the die, to “reuse” them, hence you get higher luminance, or surface brightness as we used to call. Check out DrJones’s thread here .