The goal race was two days ago, thought I'd update with the results if anyone is looking for a review of the low mileage 2Q training plan.
It was pretty warm on the day (20C), but I felt confident with sub3 after a 28k long run at goal pace a few weeks before. I went out looking for the 3h pacers (they'd started about 40 seconds ahead of me). After catching up with them, I found a huge crowd directly following the pacers. This made it hard to hit the tangents of the corners and caused pace fluctuations around narrow parts, so I passed them a bit to get some space. I ended up running the half in 1:28 low feeling pretty good.
After about 25k the fatigue started setting in, with the hard going really starting after 32k. My pace dropped a bit in the last 7k, but was still able to hold on for a 1:29 low second half for a 2:57 overall.
Reflecting on the training plan, I think the workouts in 2Q are really excellent. Due to the extensive explanations of the purposes of each pace, it really felt like each workout day was about attacking a certain system to boost it, which I found particularly motivating. Average mileage over the 18 weeks was about 36 miles, but with some weeks over 50 after consulting LR with this thread. If I were to run another marathon, I'm inclined to use JD again but with a higher mileage. I felt I really had the target speed down, but with only a bit of endurance lacking. 2Q in general I highly recommend, I might have gotten a bit lucky with hitting my goal on the low mileage, but it does seem that it's possible to sub3 on it with a few peak weeks.