The fork clearance changed between the original S40 and the current model, right? I thought I read that somewhere. Maybe. I have the first year S40 and am wondering if I can buy the current fork to gain additional clearance for larger tires or, more likely, fenders for my current 650Bx38 tires.
Rods, does "touring" mean self contained tours carrying luggage? Camping gear? Are those rail trails paved or no? How much performance are you willing to sacrifice to durability and flat avoidance?
The Conti GP4season is skewed too far in the direction of durable/impenetrable/heavy/slow for my uses, even though I'm gearing up for loaded touring on possibly graveled trails this summer, but your needs may be different. Also, 28mm wide tires are not very wide now that 28mm is the new 23mm with respect to bicycle tires. I'm a fan of Schwalbe tires and if I were in the market for 700c tires for your use case would consider the Schwalbe G-One Speed in 700x35 (see
https://www.schwalbetires.com/bike_tires/G-ONE_Speed). At a more popular price point the Panaracer Gravel King is a well balanced tire for general purpose riding (see
https://www.probikekit.com/bicycle-...V0eDICh0XvwtDEAYYAiABEgIj3_D_BwE&gclsrc=aw.ds).
Whatever tires you decide on, enjoy the ride! Tires are so much better today than, say, a decade ago, there really aren't many bad choices.
-Jack