i noticed the PI is thriving this year. i try to stay on top of it and spray it with a targeted weed spray every year (I use poison ivy killer, only targets viney stuff including oriental bittersweet), this year the plants are bigger with huge leaves.
good luck with the knotweed, there are a bunch of different removal strategies out there (most are voodoo), but unless you use ROund Up or similar, you are unlikely to succeed