Erwan,
I have concerns regarding the structal integrity, weight and platform rigidity of your beam design along with the increased setup time.
I am not saying it would not work because I have not tried it and would be very interested in seeing how things work out for you.
I will look at trying wings to increase righting moment without having to run a tilt trailer or increase setup time.
The wings stay on the boat and just fold up when being trailed.
I know there are many who believe what I'm planning will either not work or not be practical. But still think I can make it practical and also make it work well.
But like you I'll never know unless I give it a go.

Good luck, I hope your concept all works out.

Regards,
Phill