Just to be clear, I'm saying that I don't think it is great to route the barcon cables all the way up to the stem. On my barcons I routed the cables out the bottom of the tape at the beginning of the curve up from the drops. I don't care for having the barcon cable under my fingers on the drops.

Externally routed shift cables were the norm on Shimano brifters until just a few years ago.

I think I still have some NOS Suntour ones if you need any.

Thanks, I found some but ended up not putting barcons on that bike anyway. The other bike that might get them has DT braze ons so the standard Shimano adjusters will fit and I have some of those.

My shifter cables do run under the bottom bracket, so I can see if the cross-cross method works. But then it will be good bye Flickstand.
The frame I’m going to be working on already has one of these on it. (Photo by Bruce27 from the linked thread)
https://cimg4.ibsrv.net/gimg/bikefor...beecceedb.jpeg

What side mount type?

Same as you posted, but before you added the picture. I see what you mean - I thought the flickstand would ride higher.

It seems even people with modern bikes and brifters will want to keep everything under the bar tapes and do the crossover method in their cockpit. So it seems the shifter bare cables crossing back to where they are supposed to be somewhere under the downtube is a modern fact of reality now? Isn’t that hard on the cables and presents yet another problem of bare cables rubbing against a painted surface, the downtube?
https://cimg6.ibsrv.net/gimg/bikefor...dac71b726.jpeg

I wouldn't say that crossing cables is universal. It usually doesn't touch the downtube, and won't hurt the cables.

https://cimg2.ibsrv.net/gimg/bikefor...3631a2a600.png

Nope. You are not paying attention. Your method is to route the RD housing to the left cable stop and FD to the right, and have the cables cross under the downtube. My method is to route the RD housing to the right cable stop and FD to left, BUT have the cable housing go past the headtube, and then come back around behind the headtube. Such that the two cable housings cross one another just behind the head tube in an X shape. The cables themselves do not cross each other under the downtube. This latter method is seldom used because it typically does not work with conventional bolt-on cable stops which are too low and too forward. I know it works on the older style clamp-on chrome cable stops which put the cables roughly at the midpoint of the downtube. It should work on any cable stop which places the cable at midpoint or higher .

Oh yeah- since the OP mentioned mounting barcons- it is possible to shorten the barcon cables enough that they do not touch the head tube:
https://cimg0.ibsrv.net/gimg/bikefor...6a8438317.jpeg
In this configuration, the cables do not touch the headtube or the frame in general, and it shifted perfectly fine with no discernable friction. (I had to abandon this setup later because the cables interfered with my front randonneur bag- but that's a whole 'nother story)

Another trick I use , is to put a zip tie where cables cross in front of or behind the headtube. This will stiffen the cables in the cross-wise direction and force them to splay out around the headtube:
https://cimg9.ibsrv.net/gimg/bikefor...88d9af128.jpeg
https://cimg5.ibsrv.net/gimg/bikefor...a95d75d3f.jpeg
^ The cables do not touch the frame on my Nishiki Linear or KHS Aero Comp

So you are describing the housing essentially being hooked on each other in the 5 or 6 inches between the head tube and cable stop?

Or are you describing the housing crossing each other twice - once in front of the headtube and once again just behind it?

And are the housings crossing each other below the downtube or above?

I have a hard time picturing how either doesn't involve housings rubbing on the downtube to get to the side cable stops.

Exactly. Crossing once in front of, and once behind

Above. Although when I bought my wife's Bianchi bike, it came with Campy Ergo shifters, and the cable housings were routed in this type of double cross fashion, but under the downtube. It did work and it did keep the cables off the frame but the bends were a bit extreme. If your cable stops are further back and set low, under the downtube could be the best solution because the lower headset cup will keep the cables off the headtube.

If you are running to side stops on a chromed band, what is keeping the housings from rubbing the top of the downtube 2 inches from the headtube?

And I recall on my Technium with bottom of downtube stops that I also just cut the housings so they missed rubbing on the headtube.

I’m having trouble picturing this arrangement - any chance you have a pic of such a setup?

You would have to zip tie the crossing to force it to splay out. It helps if the cable is going upwards and more naturally away from the down tube. If it's parallel to the downtube it's much harder to prevent them from rubbing.

Sounds like a tall bike solution.

I don't. My wife's bike came like that (but under the downtube) - that's how I saw this in action. But I am about to change the handlebar on my Nishiki Linear, I might go with this routing (with the cable stops flipped upside down). Stay tuned!

I can see it working like that, just not when the stop is on the side of the tube.