[TOGoS]

I had about as much luck trying to find a countersinking router bit for 5/16" holes on this site as I did elsewhere. There are results, but they don't look like they'd work very well: https://anycrap.shop/product/5-16-inch-fluted-router-bit-wit...

[tempodox]

Reverse-ratcheting routers and self-sealing stem bolts looked similarly dubious. Epiphasic devices still seem to be a challenge.