But they would be IllegalI have just ordered a thumb throttle I found on Aliexp a little bit different to the wuxing offerings and the main feature is ' providing steady and sensitive control of speed', so sounds like it should be a graduated one which will be nice. A bit wider at 43mm.
https://www.aliexpress.com/item/E-bike-Parts-185cm-Bicycle-Speed-Control-3-Wires-Thumb-Throttle-on-225mm-Handle-for-Electric/32907768205.html?spm=a2g0s.8937460.0.0.2a052e0eb8G5Fy
I like the 50E even at 14s would be ideal for my 48v controller set up, if it wasn't for an integrated set up.
In Uk 14s battery yes, throttle no .But they would be Illegal