I notice you are working the screwthread "dry", have you ever pre-soaked the dowel in BLO beforehand to see if this gives a better surface fininsh to the threads? I know When I make threads by hand BLO helps give a much better finish as well as making it easier to move the threadbox
Droogs, soaking the dowel with oil works well (on many woods) with the traditional threadbox, but in my experience it doesn't do a lot for you when using high-speed cutters. The swarf can stick together & gum up the works quick-smart. That may not occur with the OP's amazing setup as the business area is more exposed, but it certainly does with my more Heath-Robinson threading jig. Waxing & polishing the blank can help to make it run through the jig more smoothly, but I usually don't bother:
I've been making & using wooden threads for more than 35 years and made at least a half-dozen different styles of taps, but I always use the above setup for threading, mainly because of the bone-hard woods we have to contend with in Oz. A traditional cutter blunts after a few turns in many of our woods, but a carbide router bit will cut miles of thread without complaint.
The screw on the tail viseof my work bench has been doing yeoman service for over 30 years & shows no sign of flagging - I think it will see me out.
I made myself a portable bench a few years ago & just for fun, I made all of the vises entirely of wood:
The guide rods on the front vise are she-oak (Allocasuarina torulosa), which is a very hard, tough wood. I was a bit concerned about how they would fare given I live in a climate with extreme humidity swings, but so far they have been fine. I think I've waxed them once since I assembled the vise nearly 5 yeas ago.
It's been to a couple of wood shows & had lots of interest & requests for plans (difficult to oblige when I just made it up as I went along!). At home it usually sits in a corner so I can use the twin-screw vise for cutting dovetails & tenons (after clearing off the junk that inevitably accumulates on it!). I made the undercarriage so the top sits about 150mm higher than the surface of my main bench, which makes it very comfortable for these operations:
(Looks a bit tall & spindly, but the wood it's made from is forest red gum (Eucalyptus tereticornis), which has a density close to 1.2, so it's rather hefty for its size & sits pretty solidly!)
One of my other uses for wooden threads is for making handscrews - I have a wall full of them & couldn't live without them.
You can probably gather that I like wooden screws too.....
Cheers,
Ian