Nick - the target audience for your question should probably be veteran PCT thru-hikers. Talk to them, and I suspect you'll find that Driducks or equivalent are both workable and preferable to more heavy-duty options, all along the trail.
I used Frog Toggs back in 2001, along with an umbrella in WA. The Rain Wrap is a great concept for high-metabolic thru-hiking, since keeping rain off the lower body during a thru-hike is primarily an issue of comfort, and comfort is mostly a thigh, crotch & butt area matter in this case.
Perhaps the bounce box could be used to carry a backup Driducks jacket, to allay any concerns about durability.