This would be a great route as it uses a southern class 171 turbostar (the only company in the uk to use a class 171) and has a single track for some of it which would be a nice challenge, if you want to go back to the old days you could even have the slam door class 205 in connex south central or network south east livery. Overall this would be a lovely route with great scenery.
I agree as the route is close to me. If you are interested in routes in the Hastings area, you might like this excellent Hastings-Tonbridge line. https://backdatedtrainsim.weebly.com/route-downloads.html
I would love to see the Ashford line, especially as an extension to 1066DC. There are not a huge amount of routes to drive the wonderful Thumper realistically, especially going back to the 1980's.