I have been using this knot thought by a Jap when I started jigging back 5 years ago.. I can surely said after tying all sort of knots I could search on web, this is one superb knot that stays with me until today for my popping as it truly exhibits 100% knot strength.
the same as you do with FG except that you do a figure 8 on the leader where you thread your braid up and down thru the figure 8, tighten it enough before applying 3 ways equal force so the braid bites into the leader, rest of the steps are no different from FG. If ever an FG will slip, this PR knot or some called improved FG will never. On top of that you can half the number of braid wrap or turns as compare to FG. Faster yet felt secured when one maximizing exposure during feeding frenzy.
As to whether this knot is suitable for popping, my personal experience is leader not more than 130lb for PE8 rod and decrease the lb accordingly with lower PE. The max I have ever tried was on 170lb leader but leave the bulge outside the guide..
Hope this helps