As a mental warmup to the idea of re-purchasing the MPC and use it as a creative sketchpad groovebox rather than something to achieve radio ready mixes on, I took an old project that was already mixed on the MPC and exported the stems to get going with mixing in the daw.
But oh my god the export feature and overall workflow and UI is so confusing! 
It works reaaonably well for normal Programs, but exporting a drum program is a living nightmare. It seems like if you route pads to a different Submix channel, those pads will for whatever reason be rendered as silent stems. And routing them to a different output means foregoing the inserts, which means the stems wonāt come out the way you heard them on the MPC.
Converting a Song to a new Sequence is also littered with bugs. Nevermind the fact that tracks and programs need to be aligned across sequences because I had already made sure I did that - but it seems to make all sorts of pad and track mute mistakes when converting. It boggles my mind that it can play a song perfectly, yet fail to render that as a new sequence! How can Akai not have tested this at least once after all these years and noticed the obvious bugs? Is anyone working on QA there? 
Anyway, the only half decent way to export all pads of a drum program I could think of was to export the Submix itself as a stereo track and do it one by one or in groups of related pads. I have to Solo both the program and the relevant pads first. At least this method seems to work. Iāve tried other things like exporting to different outs but for some reason I still occasionally end up with silent stems. It really is a mess.
And letās not even talk about how once youāve soloed something, you have no idea where you need to go to unsolo because it might have been a track, or a program, or a sub mix and thereās no easy way to tell on which page youāre supposed to go to. Itās like Akai added the Submix paradigm without ever testing the core functionality and they donāt really want you to use it. I even restarted the project a couple of times because I assumed it was a bug, but eventually I found where I had Soloed something.
Last but not least the explode track feature. What a mess with the naming of the tracks, the UI to pick track, no way to group and re-merge tracks again, no way to remove multiple tracks at once.
If I get an MPC again, I definitely will avoid things like Submixes at all cost and keep things simple and flat instead to ensure I can export and mix easily. No fancy routing to Submixes and probably no Sends either. Linear, flat routing and minimum of mixing, an eq at most. Basically Iāll treat the MPC as a more capable Syntakt and pretend the more complex mixing capabilities donāt exist.
Sorry for the rant. I wish Akai was reading it but itās been years since I first discovered some of the above bugs so Iāve lost faith in their appetite for quality fixes.