i really don't think the net will have any positive affect on the plant. it seems to me like unnecessary stress for the plant. but as i said before, i have never heard of doing anything like it. so you won't know for sure until you try.

if you want a smaller more "dense" plant the best mothod to use would be topping(or FIM) and lst(low stress training) i just don't see how a net could achieve your desired outcome. whatever you decide, good luck. remember if you are new to growing the best thing to do is stick to tried and true methods and above all else keep it simple. you will have time to experiment when you have more experience with your grow space and how mj grows.