I saw a 3D-printed Technika board/pinhole selling from somebody in Canada on the auction site. The idea is a good one, although I would have some minor doubts about how robust the PLA/ABS might be to knocks and such. It would need a high percentage of infill both for strength and opacity. I had some 3D-printed 3mm lensboards for a 7x5 Seneca which needed 100% infill to be really opague, and even then I put 3 coats of matt black paint over the top. They were very rigid though.
The other concern is the quality of the pinholes themselves: that's why I would recommend sourcing a known high quality pinhole and glue it to a metal Technika-style board. There are quite a few no brand Technika boards drilled for a Copal 0 shutter (about 32mm I think) on the auction site for about $25 or so. In terms of pinhole quality, PinholeEdun uses micro-cobalt drilled pinholes, which a metallurgist friend examined under a 100x microscope and found a variation of about 3 microns in the pinhole. There are others (like Reality So Subtle) that sell laser-drilled pinholes.