I'm a bit confused, are you saying you worked around spotify's ratelimits by using non-spotify APIs to achieve similar things? Why not just RE the official client and use the same APIs it uses? (You can get lossless that way, too!)
I looked at lossless too, that is probably possible, but im not going to implement it. It uses a different key system called PlayPlay. If I manage to implement it, it would be considered DRM circumvention and I dont really want to mess with that tbh