I agree, it's a great resource for anyone who likes to stay in one program. Once you get started on something, you may not want to take the time to switch to another program. G.Projector can be super helpful, despite it's age, especially for those of use who don't have the mathematical prowess (or patience!) to attempt a project like this. Dunno if you're interested in taking a look (or if you've already seen it), but Mar Rosenfelder - creator of Verduria and some pretty decent resources for world building - explains here how to create sinusoidal maps from scratch. I doubt there's quite as much math involved, but it's interesting. Especially since you could print out a sinusoidal map and make a globe out of it!
With your patience and attention to detail, I'm looking forward to seeing more!