I believe there ‘may be’ some cheeky stuff in Farley Mount. Bear in mind that’s it’s chalk! There was talk some time ago of building official trails and am sure there’s folk on here that can explain what’s happened or not happened.
In the past I’ve taken the byway from Farley Mount that leads to Berrydown Farm and from there I’ve gone past the rather remote Farley Church. Fast descent through Parnholt Wood that will take you to KS.
Another option is to use the byway through the wood in a N direction, L then R towards Folly Farm. You can make a loop through the woods behind Crawley.
Haven’t used these tracks for a couple of years so can’t comment on conditions.