In this suggestion, it would be nice to have a minor extension down the SEML from Ashford to Dover Priory so that Dollands Moor is included and have Ripple Lane freight sidings expanded to futureproof the route for a class 92 dlc as they operate freight in real life on HS1
They already extended it once, and that was a one-off. If anything Ashford to Dover Priory should be a separate DLC. Before that happens, though, other UK regions need to be explored (Eastern Region has no representation, whilst others have little).
I have suggested similar in the past and I would think this kind of DLC would be its own thing rather an extending SEHS. I wouldn't just limit it to go between Ashford and Dover Priory via Folkestone as it is a rather short route. I would also include Canterbury West, Sandwich, Margate, Ramsgate, AND the Marshlink to include the Class 171 to add variety to the much beloved D) Electrostar 375.