Your comment jogged my memory: it is also possible to make a microprocessor-controlled device to put inline between the motor's Hall sensors and the ESC, to advance the timing. While that involves a little hardware, the result would be usable with any off-the-shelf ESC (eliminating supplier problems), and negates the requirement of determining anything about unknown protocols.

This sounds like a good project for Jebarus, and would definitely make his dyno much different than anything else available! It really would be neat to automatically determine the optimum timing advance curve for any particular motor. But we still need to know if there are any ESCs available that permit downloading a custom timing curve, and the format necessary to do so.

I made my own such dynamic timing module many years ago, but it was not updateable via a serial connection.