Sending emoji via SMS with UTF-8 (rather than UTF-16)?

Trying to find out why emoji caused even short messages to being sent as multiple chunks I came across this question, explaining this happens because they are encoded UTF-16 rather than ascii.

My question, now is: is there a way to have them sent in UTF-8, instead? Most of the messages I send contain many latin letters and very few other characters, so they all should be much shorter if encoded in UTF-8: is it possible?

I'm running Cyanogenmod 11-M12 (Android 4.4.4) and, in case it matters, I use the SwiftKey keyboard.

In case this is not possible, is it a matter of the SMS protocol, or is it due to the OS, or even to the keyboard?

Thanks a lot!