After some perusal of Mountaineering: Freedom of the Hills, Terri figured out that you could make a lightweight temporary harness with a sling and a carabiner. I was going to buy slings anyway for top-roping so it worked out perfectly. So we're going to bring:
2 slings (120cm)
2 locking carabiners
1 belay device
30' of 8mm rope (I would have taken 20 but this was a precut length)
I was going to just bring some of my prusik cord, but that's only 6mm and iffy in the belay device. What's cool is that we can also use this setup to lower packs down the ledges.
I'm also bringing some personal oxygen to see if that helps me with AMS symptoms. It's a little more weight to carry but after years of struggling with this it seems worth a try. I'm also really encouraged to see that if I spend 24 hours at a location then I'm much better off. This plays hell with group climb schedules but when I'm going it myself it's fine. For this climb if I'm not doing well at LBSL then we can stay another night there (Oh darn, another day in paradise.) Just need to plan for another day of food.
I'm still a little concerned about only bringing the stretch polartec, and the wind shirt. The stretch polartec is great but since it fits close to your skin it doesn't trap as much body heat. Fortunately, we will only be climbing during the day, but those evening trips outside the tent may be a touch cool. I'm thinking I should go test this out at the beach some windy evening.