rickT said:
I am not using brake cutoff levers, but do want a thumb activated button (normally open, press to close) to cut off the motor at times. Grin says they do not sell such a button but if I find one I could connect to the open brake cutoff connector on the CA. Can anyone recommend an available button switch for this? Either handlebar mount, or able to attach to the Grin digital aux switch unit.
Other than the solutions already posted, you can change the switch out on one of the momentary-button types to use a latching switch instead. Most of them use a standard PCB-mount (though not usually on a PCB) like this randomly-found version:
https://www.ebay.com/itm/284575784318
though some use other types.
If you happen to have one of those turn-signal/headlight/horn combo switches on the bike, and are not using the horn, all the Wuxing ones I've used have the above type of switch in the horn, making it easy to swap out. Or use the headlight rocker switch if it's not in use, as that is already latching.
There are also motorcycle handlebar switch modules of many kinds, from one to several buttons, like these:
https://www.ebay.com/itm/184444155621
which simply bolt or screw (using the provided plate) to whatever convenient other handlebar mounted thing you have, so you don't have yet another ring to clamp to the bars. There are also fully-enclosed versions with their own clamping ring.