Start by saying it works;
Axoloti MIDI DIN OUT does power the Yamaha MD-BT01.
Don't have a mac with Bluetooth LE, so only used iOS devices.
Playing notes OK, sending 10/12 MIDI CC's seems to "blow up" (BT communication) ehehe.
How low bandwidth Bluetooth LE is? 8x MIDI (not my field)
But again it works.
Related:
Only device that i found NOT working is iConnectMIDI2+, does not provide enough power...weird.
I'd imagine it is hard to drive (deliver power) a midi input with power harvested from a MIDI output. This could show when dense traffic appears, like sending a dozen CC's in a burst. I'd rather refer to Yamaha's customer support...
iConnectMIDI2+ with Axoloti not working
or iConnectMIDI2+ with MD-BT01 ?
Hi Johannes,
I am merely reporting, no complaining whatsoever.
Yamaha MD-BT01 has no batteries and a bit strange as you say harvest power from MIDI out of instruments/MIDI devices,
and because of this, Yamaha MD-BT01 does NOT work attached to an iConnectMIDI2+.
I have raise this to iConnectivity.
http://www.iconnectivity.com/forum#/discussion/1257/resolved-yamaha-md-bt01-with-iconnectmidi2
Sorry if my response looks as if I'd be irritated by your post, I'm not.
MIDI wasn't really designed to be used as a power source.
I checked your thread on the iconnectivity forum, if the Yamaha MD-BT01 depends on 5V, the list of incompatible MIDI devices will grow, since the MIDI spec was updated to 3.3V signalling https://midi.org/specifications/item/midi-din-electrical-specification in 2014...
no problems, Johannes 
I'm contributing to Axoloti world as I can...
MD-BT01 must have left iConnectivity guys a bit perplexed.
And yep maybe you're right, incompatible devices will grow, so in my studio all gear is a bit old, thats why it works with
everything.
No matter what it works with AXO and can be used in many ways and things evolve and get better (in the future).
So, I'm playing around with a MD-BT01 now. I get it powered up, and I can connect to a Mac so that the Mac receives MIDI from the axoloti.
What I want to do, though, is for the MD-BT01/the axoloti to receive MIDI over bluetooth from a Seaboard Rise. Since the MD-BT01 is supposed to work as a MIDI out and in, this should be possible, but I don't know how to pair the MD-BT01 with a sender that is not also a receiver (i.e. another keyboard).
Anyone have any bright ideas? That would be much appreciated, given that, as I remarked on a different occasion, the USB midi outs of the Seaboards seem to tend to die after a while...
I don’t have a Seaboard, so can’t try but..
It’s a case of pairing both the Seaboard and the MD-BT01 under either a Mac of iPhone/iPad
and there, route MIDI as you like 
