I was having this same problem. Haven't mastered it yet, but i realized that i was having trouble cancelling to lm from trait because i was trying to buffer the whole thing. Buffer the whole thing up to the trait, THEN wait a split second for the animation for the trait to start, and cancel to lm. You'll eventually get the timing and muscle memory with help from the sound effects telling you where in the rhythm to cancel. it's not as hard as it seems once you realize that you just have to wait a little longer for that db1. Don't cancel to lm until the trait animation has started. Other people may have superior methods, like I said I'm by no means a pro, but I found this helped me.
On a related note, I seem to have trouble consistently meter burning lm online. Its funny cuz whenever i test it in practice, the window for burn input seems HUGE, but sometimes online I mash the crap out of it and it doesn't seem to want to burn. I'm at work so I can't verify right now, but it seems to be worse after certain strings. Any advice on that would be appreciated.
