AFAIK, no one else has done this. It is far from an ideal build. I replaced the stock motor from the cheapest cordless Sunjoe mower available with the motor from a Kobalt 24v weedwhacker. Reason is that the Sunjoe mower has a non-swappable battery pack. You'd have to take off the top of the mower to change it out. So, if you didn't finish the lawn on one charge, unlikely, you'd have to wait to recharge to continue.
I started with the stock Kobalt controller, but it burned up within half my yard getting cut. Then I tried a $20 POS from Amazon that had no programming capability. It also burned up in minutes AND pulled so much power the battery got hot. Finally, a Flipsky mini is onboard handling the load just fine. Battery stays cool and the motor is happy.
VESC is an awesome project! Thank you!
Pics and a vid at the link. https://imgur.com/a/vE7mFad