So it's all ready! I've made a special cable from a useless headphone, notice that only one channel (two ear plugs) work with the JMI controller... You really got to check before the soldering work.
Notice that the wire from this headphone is a kind of crazy, it's a *single* coated wire only! But that's enough to drive the small focusing motor.
The original coiled cable is good, guess what I have to made this silly cable myself.
Yes, here's the answer, you see that the plug stand up quite high.
And this one is just far more low profile:
And only this one can clear the base of the mounting plate, the original cable is too high profile.
A tube ring is of course more desirable for the mounting both due to the balance and security, but then it also means extra cost and weight. I will settle for this solution right now.