Also another thing to finsh that choke is to work a higher mount. Slide your knees tightly up their ribs to almost their armpits. Then place your head on the ground above theirs while pulling them up into your chest. "Fishing" your wrists for extra leverage.
I personally don't like mount unless it's for mma or points. Mount seems harder to isolate a limb compared to side mount. Plus i like to take the back which i have alot of set-ups from side mount.