For those of you who are always struggling with connectivity options/problems with the MojoPoly, and whether to use your iPhone's hotspot, the MP's hotspot, hybrid mode, AirPlay versus music on the mSD card, Glider versus other MPD apps, my solution is to simply buy an iPod Touch, either store your music on it and stream via AirPlay (e.g. if most of your music is 44.1/16 RBCD) or store your music on the mSD card (if your music library has a good amount of content in hi-res or DSD) then use the Glider app. You set your MP to use its own Hotspot mode and your iPod Touch would become the control hub with the best touch-based control interface compared to any other dedicated DAP out there, the exact same feel as your iPhone/iOS device. Then your iPhone will just be limited to doing it's smart phone related duties. When you travel abroad, there is no need to cater to or worry about roaming with your MP and whether streaming music locally stored on the iPod will incur roaming charges, because you'd still be using your MP's hotspot. Any data usage is on your discretion limited to what's used on your phone.
Of course, I am not a subscriber of Tidal, Apple Music or other online streaming services, as I'm talking strictly about music you own and can download to your iPod without needing internet access to play, and music files you can copy to a mSD card.