However, we're not fundamentally a fitness program. While we do carry around some fitness data to convert to formats like GPX, we leave specialized niche data to programs specializing in that. Crank power was already on the outer edge; different crank torque for each pedal isn't something I'm terribly motivated to add on my own.
What we know about the Fit spec has been reverse engineered. While they provide documentation, their license is so completely incompatible with an open source project like ours that nobody working on code can look at it. (We can't exactly ensure confidentiality of knowledge derived from their specification when we publish the source code...)
If you have information about this "new .fit" and want advice on how to implement it, ask away!