If your FOSS application interacts with a web-based service that requires an API key, the correct way to implement it is to instead have it interact with your own servers, and in turn have your servers interact with the web service via the API key. You should of course then publish the source to the server-side part of your application as well, and advanced users can then (if they really want to) setup their own server, with their own API key for the web service; this also protects users from the possibility that you disappear and shtudown your server or let it rot.
Of course this design assumes it's a web service your users are accessing anonymously. If they have to login to their own accounts, then this model is usually wrong. They should never be providing their account credentials to you, and it can only work correctly with more advanced authentication methods that avoid the need for them to provide credentials to you, which the web service is unlikely to support.
I really want to add a Bionic comparison, but in order to be comparing apples with apples (or non-apples with non-apples, pardon the pun) we need an x86 build of Bionic, or need to re-do all the other libcs' figures for arm. I've been looking for a way to build Bionic outside of the Android build system and use it on non-Android systems, and the gentoobionic repository at https://github.com/gentoobioni... looked promising, but I couldn't get it to work. It also may be much larger than the official Bionic.
If anyone is willing to help us figure out how to setup x86 Bionic for testing, please stop by the IRC channel (#musl on Freenode) or send a message to the mailing list.