Thank you guys.

And yes, DD, that was for your eyes mostly, to check that your babies are well treated...

And i'm going to "re" try a FFB sterring wheel to understand what was making this way of leaning so great and efficient.
Better that a joystick.
And more smooth and controlable than my handlebar.
Because what i think last time i tried, is that actually FFB effect was off on GP Bikes and only the fact that "basic" FFB was on, meaning the come back to the center position.
And that centering forces against you constantly. Giving you something to counter-steer and at the same time, avoiding the handlebar to wiggle left and right, making me loose the benefit of a handlebar position as on my bike.
A little bit as a steering damper but this element smooth the mouvement but doesn't force against you, just making the movement more linear.
If its what i "feel" then FFB is not necessary. Springs are theoricaly enough, except they don't force on a linear way and tiny force at beginning, big at the end so it's not springs the solution. I've tried a lot of them, different position, deifferent diameter of steel, all kinds of solutions, its not as it was with the steering wheel + FFB minimum that i recall in my mind.
I'll try tonight with the one i'm stealing and then i'll have my answer.
If its "just" a matter of having a DC motor forcing against my arms to take it back to middle position, i guess that's a lot easier to execute then a real FFB device.
Need a encoder to read the angle, a DC motor, a little electronic basic to rules the motor, probably a old Power Supply for computer and the bigger work will be to calculate the gearing for the reduction. Or go with a belt.
Well, it's not finished but yeah, it's coming !!!
(the real thing will be to have hard time leaning as i brake in curve, as in reality and that's really troubling me that when i brake and lean, it's not harder to do, i'd like to be seating there, and have the same feelings... The Graal !!! )
Oh, and DD you're right, i did put 100 direct lean and it's way easier at least with a handlebar.