Why is your plans to keep the Mechanical brakes?
They wouldn't be needed really.
Oops missed that one piece.
As my current plan to run the 1717 on the MMM 5S at first and then 6S, heard a lot of mixed opinions about the 1717 and MMM, thought to go safe, and plus i liked the challenge. Wouldn't you think it relieves the ESC of additional stresses.