I didn't have much luck with the teleconverters for this type of work, the extenders worked better. They are inexpensive and the Kenko ones will pass the lenses signals thru to the camera body.
Direct Write E-Beam is still around but hasn't made any impact for the reasons you describe. GaAs has made some in roads but is being displaced with CMOS, SiGe and GaN in most new applications. I don't work for IBM, but we had a small fabless design group that was acquired by ITT in 2006. If you have access to the IEEE, check the Sept 2005 issue of the IEEE Proceedings, we were invited to publish a paper on SiGe Radar applications. We do mostly government work, DARPA and such.
Funny but the commercial silicon fabs have completely outrun the government's ability to keep up in silicon technology (CMOS specifically), so the government is riding on the coat tails of commercial work at IBM, Intel and others. The new chips these folks are producing with devices so far below the defraction limits of conventional optics, all the conventional thinking folks are accusing Mother Nature of fibbing!! Moore's Law keeps marching on!! However, I remember the commercial where it said, "it's not nice to fool Mother Nature", so she may have a few surprises for us in the near future!!