Developing a guard game no gi is not easy. Especially for athletes crossing over from gi jiu jitsu with the abundance of grips. Since we are limited in our grips in no gi we have to make full use of both our upper and lower body. This might also explain the usage and acceptance of lower body attacks in no gi.
Common issues that I see with lower belts is that during grip fighting exchange their attention is spread out over two or three different focuses. From this also not knowing when a guard is compromised and no longer defensible. If you underrated these two major details. Your guard game is sure to level up.
The darce choke is one of the most popular and high percentage chokes from side mount especially when your opponent turns into you to recompose their guard. Definitely a move that will be used a lot this year.