Did the trail a month ago - finally getting around to reporting back. This is not a trip report by any means, but few tips on hammocking this trail for those interested.
My set up was a SWT, DIY gathered end hammock, JRB HRTQ and MWUQ with a DIY neatsheet multi quilt that went under the UQ for protection. For suspension I used whoppie slings over a marlin spike hitch. Bring lots of extra webbing because the trees are big - I brought 4 8' lengths of webbing and needed it all one night. This set up worked really well for me. Water is very plentiful so never need to worry about that, never carried more than 2 liters. footing is very difficult (mud and roots) making the walking slow, but the hike is not really difficult unless you carry to much weight or don't bring poles. I was baffled at the enormous packs most people were carrying. I did regret not bringing crocs for camp shoes and crossing rivers.
In general, I try to avoid the marked camping areas just because I prefer to be out and away from people. My usual rhythm is to find a site before a designated area, camp there, then pack up in the morning, go to the designated area, get some water, have breakfast if there is a nice spot, use the outhouse, then keep on going.
On the WCT you can camp anywhere you like, except on the reservations which are clearly marked. the challenge in finding a good hangin' site is the density of the forest and the undergrowth. the challenge of hangin' at the marked sites is that they tend to be on the beaches and without alot trees. From what I could see most of the marked sites had doable spots for hangin. These sites were well populated, in fact a little crowded, and there was some litter to be found at many.
I went south to north. First night I found a great spot at the top of the beach access at km 65. On the second night I pulled into the marked site Walbran Creek and was pleasantly surprised, found a good hang from a couple of trees at the edge of beach along the creek. My third night I thought I would try a marked site again given my success the previous night, so I pulled into Cribs Creek site. This was not a great looking site, and it started to rain so I set up anyway, actually blocked off a bit of path, and it got very crowded in there - not recommended. On the plus side I enjoyed the company of some folks and good fire that made up for the steady drizzle and tight quarters - and woke up to full on sunshine which lasted most of the next day, which was a long day. I was beat by the time I got to Tsusiat falls but there wasn't a tree to found. So for the first time in 2 years I slept on the ground. turned out fine though set up took awhile and the wind was fairly strong but thankfully died down and the night was calm. The beach actually made for comfy sleeping. If I did it again I would look for a spot at Tsusiat Point or press on and find a spot off trail or go to Klanawa. My last night was my best. I took a side trail at km 9 (just north of Pachena Lighthouse) down to the bluffs. I don't know if you'd get two hammockers there, but I found a couple of trees, one was so big I needed 18' of webbing to get around and tie the hitch. There was a bunch of sea lions on a big rock next to the bluffs there the whole time I was - didn't actually get why they were called "lions" until they roared - pretty loud they were.
That's it - was an awesome trip, definitely doable in the hammock.