A couple clarifications:
1) ALAC and AAC are open source formats, even though Apple authored them.
2) Lossless formats like FLAC and ALAC can be converted back and forth with no loss of data.
3) My home computer is a Mac and Android transfer to move tracks from my Mac to an Android device is a horrible experience.
4) Using iTunes to drag and drop music tracks into the Onkyo HF app folder works great and wirelessly.
I did buy a cheap Android phone as a transport (Sony Xperia Z5 Compact), but then I have to carry around 2 smartphone devices that do the same thing. I then upgraded to an Android DAP - Onkyo DP-X1. While it sounds great, it still falls short of CDM and Mojo, so that is why I'm back to best transport that works for me connected to one of my portable amp/DACs.
I agree the prior models of iPhone which topped out at 128 GB was not viable for my music library, but now the 7 has 256 GB which is all I will need for quite some time. Again I don't want to discuss why I prefer iPhone smartphone capabilities because it has nothing to do with audio or this forum, so I still don't see what I am missing out by using an iPhone as a pure transport. Other than UI, using my iPhone as transport should sound no different than using an AK380Cu as a transport for my CDM.