@PaulJSR My X5S came fitted with the same extruder as your X5ST. If you look closely at the nozzle cooling fan you can see that it is a bad design because the fan also blows onto the hotend!
If you decide to go with a direct extruder I have this:
https://www.amazon.co.uk/gp/product/B07C24V3FL/ref=ppx_yo_dt_b_asin_title_o09_s00?ie=UTF8&psc=1
It is a chinese clone but works well as long as you throw away the stepper motor that comes with it because it is way under-powered for the job. The design is extremely light for a direct extruder set up and less than a quarter of the price of the genuine equivalent.
You would also need to print an extruder mount and fan parts from thingiverse:
Extruder mount:
https://www.thingiverse.com/thing:2871308
The cooling fan parts are contained in a link in the above mount.
P.S the titan clone can be used as both a direct extruder system or a bowden one. Everything is supplied for both configs.
