To cut off the ring you need to be at least as fast with your feet as your opponent. Rigo had far superior footwork.
If your footwork is superior you don't need to be as fast. But as you said, Rigo had better footwork anyway. Unless you're sure you can take much more punishment, in that case you could go in while catching a lot of fire.
What I don't get is why if they can't cut off the ring do the stalkers play into the counter punchers game and come forward. Move back and let them come to you for a change. Give 'em a dose of their own medicine and see how well they come forward pressing the attack. Donaire applied the same game plan for twelve rounds and every round he's thinking, "Okay, this is the time it works!" Change gears and make adjustments for God's sake.
cutting off the ring is similar to playing D on basketball, we may have seen a different fight if nonito knows how to and use his jab as a range finder, he looks silly being the bigger man always taking the lead head hunting
I partially agree with the fellow that said your getting punched back or feinted as they're moving back, laterally, or away from you. Truth is you don't see that much bobbing and weaving anymore or jabbing at your opponent as their pulling away. That's why it is always good to finish a combination with a jab so you'll reset your opponent and prevent a counter from happening. Chavez Sr., Frazier, Tyson, and JLC were very good at this, but you want to look at a master look at Duran. Duran always liked to use a jab while chasing his opponents because by the time he closed and gauged the distance he was ready to unleash his right hand once he got there and trapped them. That is using intelligent pressure coming from what looked like an untamed animal. He was effective, wasn't overdoing it like Pacquiao sometimes does it jumping and moving all over the place and Pacquiao never learned to cut the ring off for the simple reason he was used to fighters coming to him. Duran never waited for that he cut the ring off while at the sametime being in position to counter always. He learned from one of the masters Arcel.
Some fighters have better footwork and have practiced making it difficult for their opponent to cut them off. It's one thing to watch a fight and be like "FFS why isn't he cutting off the ring?!" and a whole different situation actually being in there trying to cut off the ring against someone with amazing footwork like Rigondeaux.
In my opinion the problem, in Donaire's case, wasn't cutting the ring off by itself. He actually blocked Rigo's path with his movement quite a few times. That is why we see Rigo ducking low and spin. After 7 or 8 rounds in which Donaire was getting outboxed , he basically had three choices. 1) Stay patient and look for one big K.O. punch. 2) Double up his jab, feint, force Rigondeaux to stay at mid range each time he cut him off. Move his head and prepare to eat some hard shots. 3) Rough it up on the inside. Push with his shoulder, with his head. Smother, use your elbows, your forearms, make it as ugly as possible. Nonito went for the first. In my opinion the third option is the most profitable against a guy like Rigondeaux, but Nonito is not that kind of fighter. He could have committed more, but when he finally did, Rigo hurt him. There was no easy way out.