@reapermods has started making PWM mods using the Smart PWM boards from @stealthvape
http://www.modparts.co.uk/boards/324-smart-pwm-v2-0638183554494.html?search_query=Pwm&results=1
Great additional features over a normal PWM.
Reaper Mods Facebook is:- https://www.facebook.com/groups/reapermodsuk/?ref=ts&fref=ts
If you don't use FB you can contact Wayne via reapermods.net