Mad question - I'd like to run my Turkish 8F in a similar environment. I've not found a Turkish route so would it run on Cape gauge ? How are gauge checks performed, by the loco or route scripting ? The reason I ask is I'm sure I saw a video of someone run a Krokodil on a narrower gauge line.
Neither the route nor the loco does any sort of check. It will look very strange, but it should still work - the wheels will visually overhang by almost a foot on either side. The biggest concern would be that narrow gauge lines are generally built with sharper curves that an 8F might not be able to get around.
A good suggestion would be the Villeneuve Valley Branch from the workshop: https://steamcommunity.com/sharedfiles/filedetails/?id=1265404473 It's a bit heavy on the requirements side, and of course is set in Australia, but it makes a reasonable stand-in for Turkey I think.
Ah! I think I may have seen a video of the 8F on this - many thanks Railfan, I'll investgate the requirements.
There is the Njandoul and Linguere route on Railsim.de which is standard gauge set in Africa https://rail-sim.de/forum/wsif/index.php/Entry/1671-Njandoul-Linguere/#description A couple of other routes are also required - see the description on the lower part of the page Peter