I don’t have idea about I phone but every phone I owned in the last decade, Symbian, windows phone and even my current Android can use a .wav as ringtone. I upload the wav, did not notice that the website is going to compress maybe there is a way to download it as wav or you can use Audacity to convert it back to .wav

Okay, so what we’re looking for is what you did with “30th December Ringtone” , where each part is a separate .flac file (eg. bassline, drums).
In a .zip file you can include the full mix as a .wav, for users who don’t have the option to convert files.
I would definitely add an .mp3 of your full mix to the upload’s files and select it as a preview file, otherwise people might assume it doesn’t work because it won’t play.

Something to consider is to also save your full mix as an .m4a file, and rename it to an .m4r before putting it in the .zip file with the .wav … that way it can be used by more people’s phones.