Lots of posts claiming a BBSHD handles heat significantly better than a BBS02. I would go that route over trying to synchronize multiple simultaneous motors.
Karl is a Bafang mid drive guru, this article has statements that ought to really hit home to you
https://electricbike-blog.com/2016/0...hopping-guide/
Maybe a different chain ring while you are at it. This one appears to offset more toward the granny ring than the one in your picture, hard to tell.
https://electricbike-blog.com/2016/0...irsty-monster/