Left and right hand syncing technique

I have found that when doing runs or sweeps, the best way for me to train that locked in feeling is by taking the thumb totally off the neck. That forces your fingers to fret the notes fully as they are being pulled into the strings by the hand, rather than the thumb.
I find this fixes a lot of syncing issues. As the right hand can easily play in time as long as it’s fed well separated notes. The moment you add in a couple poorly fretted notes your right hand has to add extra force to keep up, and that will throw off even playing.