Here’s some techniques to train on your Submission Master when you have the KNEE ON STOMACH position
One thing your opponent might do, if you’re punching, is put his close arm up to push you off. From there, you’d go to an armbar on that arm.
Another response your opponent might do is to push on your knee to get your weight off him.
In that case, you can either go to kimura armlock, or armbar on the other side of his body.
If your opponent just keeps his limbs tight to avoid giving you the ability to attack them, you can change your position repeatedly to confuse him and cause him to expose one of his arms for attack.
That included putting your hands on his chest and jumping over his body, or spinning around hsi head, to go to the opposite side.
And finally, you can do a paper cutter choke, either by changing position to above his head, or by kneeling on his arm to trap it and prevent him from defending against your choke.