Found the post on keycaps:
Keycap cavities are family molds that make an entire set of KeyCaps in one shot, so many thousands per day.
No idea what "many" thousands would be. I would certainly think more than 2-3 thousand since that would be more like a "few". It could certainly be a number similar to complete sets of the butterflies though.
And I found this:
we've actually already replaced the entire keycap inventory before, twice (many hundreds of thousands of parts). If that counts the space bar, then 9/TextBlade. Still don't know what "many" hundreds of thousands would be, but taking an absolute even 100,000 would be at least 11,111 complete sets. No time frame for this though.
our capacity is many thousands per day
That also refers to the keycap sets.
On to Nano Stands:
The production lead time for the NanoStand is quick. The mold makes thousands per day
I think that pretty much covers all references to how fast some things can be done - at least at the time they were written.
Of course, that doesn't tell us anything about how fast the the chips and other stuff can be done, not anything about putting all the parts together.
But it gives some info and now, I think, all in one place.