If those are the only two files you need, can't you just make a tiny cordova plugin that adds those tags? It seems like there shouldn't be any need to fork an entire plugin if all you need to do is add a small change to config.xml - you could use the original plugins on npm and include your own tiny plugin to add those tags, and such a tiny plugin would be trivial to review and update on the build service.
Also I'm not really clear why this is specifically needed for C3 - don't the original plugins already add those tags? Why is this different in C3?