I've often been told I have an uncommon physique. No complaints yet! That said...
The set back on a TCO is about 25mm, on a Suntour XC post, only about 15mm. A Turbo saddle has 85mm of space on the rails....that seems well within the range of 'normal' if clamping mid-rail to sliding the saddle back further.
What frames do you propose would be appropriate for all the non-set back 1980-90s IRD, Syncros, Cook Bros, Dean, Litespeed, Kona, and Ringle seatposts?
Like I said, FCW specified setback seatposts. FCW has long stays so if you want the bike to handle and weight the wheels as designed you will use one. Although the Turbo has relatively long rails they are positioned under the saddle towards the rear compared to a WTB SST which has shorter rails that are positioned such that you can actually move the saddle 10mm back farther than a turbo.
RE-garding your other question, some of the Kona's came with non setback seatpost but they did not have 17.5" seatstays.......
People make non-setback seatposts because people buy them, most because they want a shorter cockpit and are clueless as to how setback is used to weight the bike & position you over the bottom bracket . IMO for the Wicked that is a mistake as it was designed around a setback seatpost. Owning one I agree. Give it a try , you might be surprised.