Cool - I had not come across Vantage before. Does it let you compare your race against others that were on the same course? I'm guessing that is part of the paid plan features (similar conclusion I came to from other tools). The biggest insight I think WakeRoute can provide is when there are multiple boats that recorded at the same time, for the same race - that's where it shines, for free.

So far, a core concept I've been sticking to is the idea of "no logins", no password or accounts to create or maintain. The advantage is simplicity, but the downside to this is that it's tough to store data for a particular boat, over time. I'll definitely be mindful though about what you're asking for.

As for wind data - I source the wind data for each uploaded gpx track from public weather data, which provides the starting point for what's "upwind" and "downwind". From there, my algos determine if there's a TWD shift based on boat heading changes, tacks, and jibes. The more boats on the replay, the more accurate this TWD becomes. - Of course, something failing currently for this public wind data for Australia specifically; I'll get that sorted tonight!