As I thumbed further through Shimano's latest technical manual, I found a lot more needless complexity than ageless simplicity. That makes the survival of simple shifters all the more incomprehensible, but that's the paradox of our Asian overlords. If you know how to ask or where to look, they're as generous as Shinto Claus.
Perhaps they realize that the only way to have a true monopoly on cycling componentry is to be the sole source for parts for the very revolutionaries who foment against them.
Hey, it works for me. As long as I can get the gizmos I need to avoid having to use the gizmos they so enthusiastically market, I can peel the labels off and laugh about it.
Paul Components of Chico, California, has even developed devices called Thumbies, which are brackets you use to turn a currently available bar-end road shifter into a good, old, reliable top-mount thumb shifter for a mountain bike. Because these come in 8- 9- and now 10-speed flavors, you can have modern excessive numbers of speeds and retro shifters with friction option.
Because cyclocross racing and 'cross-style riding has become another fashionable niche in the biking world, bar-end shifters remain on the market. But we're talking Shimano here. I started stockpiling a couple of years ago. I don't care if they're 8, 9 or 10. All I want is the friction option.
Actually, after several years riding the Cross-Check, I suspect the radius of the Shimano bar cons is a little tight, because shift cables seem to fatigue and break pretty quickly. But I may have left a burr on the housing when, slavering and drooling, I built my Cross-Check on a frame I bought from Surly just before the introduction of the model as a complete bike. At the shop, I would have used a bench grinder to smooth the housing, but at home I had to use the old kitchen-table method of cutting as smoothly as possible with the legendary Felco C7 cable cutter. Perhaps it wasn't smooth enough. But I hate to disable the bike long enough to yank that whole area apart to check.
Keep digging for the good stuff.