Optimise wound track checking

[OctarineSourcerer]

Currently, to figure out which of the wound boxes to check, there's a LOT of calling handlebars functions, and it doesn't early-exit. This is more than it needs, and is a bit of a hack - I'd like to NOT have to check a little bit of maths 40 times on loading. Once, yes. Twice, no. Might have to write a handlebars helper that batches the whole lot of wound boxes.