How to add drawstring to R1?

hey there! I really like my R1 air full zip hoody except the bottom flares out a bit. I wanted to add a drawstring to the bottom. There are some nice ways to do this, eg cut small slits in the bottom hem, apply a grommet in each slit and feed shock cord through it. The whole thing is completed with a shock cord stopper on either side. So the question really is this: is the R1 bottom hem tubular in structure to allow a draw string to be inserted through it? I thought I would ask before cutting small slits in it! Thanks for the help.