Hey there Russell. I can't seem to message you as ULF so using a very old ID instead. Any my email is firstname.lastname@example.org I to have asked Remi a few times about the boom length of the 8.5 and 7.5 . They keep telling me the adjustment of the boom. I even clarified it to get the exact measurement but still no answer. I asked Ian Fox and Remi. No-one seems to know. Anyway get me on email above or ULF on seabreeze and we'll have a chat about it.
PS sorry I cant reply as ULF it seems to be locked for some reason.