I think it's a horrible idea. It won't help the precision of your finishing technique, and it completely takes away your ability to control the distance. If you go with another form of lower body control, like your shin across their waist and other leg over their back, then you can do things like base out to the front headlock if the choke doesn't work. Or follow them to the mount if they try to roll out. The most "leg wrapping" style guillotine that you really see anymore is the straight up closed guard during an arm-in guillotine.