ESS used in M0 is SoC, all in one unit. Firstly, not sure if anybody knows how difficult would it be to work in this chip, change it's connections, software, etc. Secondly, why to do that, when you can simply decide to use dedicated DAC chip if you are already putting there dedicated amp circuit, making the device bigger no matter what. Well, you can use M0 as USB DAC with Android phone. Not sure how would you like to use M0 as source for Android device? You can connect it in Transfer mode and view files on mSD card. BT delay: You write you are using AAC, which has it's own delay caused by technology and no device on market can change that. Needs to be fixed by your phone, sometimes it can be hidden in some advanced setting or most video apps have setting for audio delay, exactly for this reason. With USB delay, working on it. I was testing early version of new EQ system recently, its sound is promising, so hopefully it will be in M5s and soon after that in M0. Card cover, some people like it, some don't. Wast majority of users puts card into their player and takes it away once in a while, so for that we made cover that fits securely and doesn't flap around that randomly. If you think yours doesn't fit properly, you can try to play little bit with the o-ring, to make it fit more flush. M0 is DAP first, so no plans to include Mic or functions to control phone calls. For that we will have UP2 with all functions of BT receiver. Regarding phone notifications, M0 in that way acts as any other BT receiver or headphones. if you want notifications, turn on the volume on your phone. Streaming is always question of the system, developing system support for streaming apps takes time and simply using Android brings many other problems. We believe our solution with using your phone and connecting over BT (or Wifi on M5s), is decent temporary way to get streaming on Shanling players, until better solution is finished. M0 can works as BT receiver with pretty much all devices sending BT, so it's all about settings and possibilities on your Chromebook Send me one file in PM to check out, easiest way how to solve such problem. Yeah, listening. Repeating posts on same topic will unfortunately not speed up our limited software team.