My knowledge of the "typical" PCT thru is a little dated and I don't know the latest regs on shipping fuel, since the TSA got involved. I think it can still go via ground and I'd try as much as possible to handle fuel resupply in the same box containing your food, batteries, etc. The PCT has far less in-town resupply than the AT.

Without a drift box I don't know how else you'll adjust your wardrobe and other gear as you progress, nor charge your camera/phone batteries, handle in-town repairs, etc. Yes, shipping it forward is an extra step but I'd weigh that against the possibility of being stuck in town awaiting repair/replacement of a key piece of gear or, heaven help you, not having your bug stuff when your run into the spring hatch. It could be that I've been visited by Mr. Murphy once too often for my own good and I'm overly fixated on the what-ifs.

FWIW probably would reship it a couple stops ahead, not to each one.

If skipping the drift box I'd probably include new footware in key resupply boxes, with the presumption that they're going to wear out with some regularity. Socks, too.

Cheers,

p.s. There was a giant fire at Belden, south of Lassen Park last summer. I'll guess it's affected the route through the area for this year and perhaps beyond.