I think you might be confusing CastAR with the C64 toy stuff she did early on. That was initially FPGA and then converted to custom gate array. If I recall there was an issue in that the FPGA initialzed it's memory and the custom silicon didn't which lead to some heart pounding moments when it failed initial bring up.

I don't think CastAR/Tilt5 isn't doing enough units to justify custom silicon. I believe they settled on the Intel Movidius VPU for the bulk of the glasses "brains".