I'll try to answer the questions
First: yes, I did it ! At this stage, only the 3/4 set has been achieved. I had ("we", actually, because two of them have been made) to check how the system is playable, and how does the mechanic works.
Big discussion is going on on what has to be improved in the future.
The reason why I worked on this project is, at the beginning, based on the following ideas:
-Regulators playing is quite a challenge, but it appears, when you get to manage with it, that comparing with what can be done on the chanter, their harmonic abilities is really a bit limited. (I know, limitations can be the purpose for musical imagination, but we can nevertheless legitimately expect more from a device worth half the price of the whole instrument...);
-I always thought three regulators as the maximum width allowed by "normal" playing. All the attempts for enlarging the system by adding more and more regs created unplayable monsters;
-some very interesting and usefull "cross chords" are availlable between baryton and bass, but only accessible with finger playing between bryton and tenor;
-I have got the mechanical training and outfit allowing to try something in order to enlarge these harmonic possibilities, without enlarging the keyboard.
Why not to try!
As you can see on the few videos I sent on Youtube, the result appears to be not such an aberration.
The most significant thing for me is that, if you don't know the system is new, you can't really notice it. Things are rather well matching together.
You can notice also I have no aims to revolutionate irish music. The purpose is only to make an instrument a bit more adaptated to answer the expectations of the music as it is.
In the matter of sound, my approach is exactly the opposite: I'm working as a mad on reeds, hoping to find how did Leo Rowsome to make pipes sounding like this !
Yes, there's a debate on wich is the best place for the E-G chord!
Things are still on progress...
Here are a few links:
https://www.youtube.com/watch?v=QBcWdcs5M_I
https://www.youtube.com/watch?v=mq-nS6OmX5c
https://www.youtube.com/watch?v=1T0bvE63pzU&t=106s
https://www.youtube.com/watch?v=dyB584etx6Y&t=50s
https://www.youtube.com/watch?v=BdqjzsvZzy4