We ended riding up Box Hill in exactly the same time Paul. I averaged 330W but am 1Kg heavier then you so it does suggest that your PR done in the Tour de Zwift did have some benefit of draft on the hillI said to Lee last night that if that ride wasn't a PR for me (on the Neo) on Box Hill I'd give up - I was 7 seconds off my best time despite averaging 324 watts compared to 314 watts for the faster time
The reason is, the faster climb was done in the Tour De Zwift so a) I probably benefited from some drafting, even on the hill, and b) my weight was a kilo less than now. I need to go on the @Whorty diet
We both need a bit of what Whorty's on (or isn't).