Thanks @_mark and @ellips_s , I really appreciate
Fortunately, I’ve found a solution today in order to achieve what I wanted to do with Jitter (I’ve read the various object references again and re-watched the excellent tutorials by Armando Gonzales and Federico Foderaro)
(patch posted below).
I was struggling with jit.gl.multiple and I didn’t understand how to assign some individual parameters to a gridshape duplicated by jit.gl.multiple. Now that I understand the concept of jit.matrix and (when to use them) a bit more, that opens up more possibilities. Even after reading the tutorials and watching some great tutorials on Youtube, some things were not really clear, possibly because there are often many ways to achieve the same thing and each tutorial demonstrates a different method.
I’m still experimenting with jit.gen though…
For info, here’s the very basic thing I was trying to do: Creating a grid of shapes, assigning a variable alpha channel to each cell/gridshape 
Code
----------begin_max5_patcher----------
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iSQZSVe1Gvglom8gab1GswkevF8+wZb9Gpghy+7g+E.F0LzO
-----------end_max5_patcher-----------
Now I just have to fill the alpha channels with values stored in a dictionary (instead of using jit.noise for the test) but that should be fairly simple, I’ll do that next year ^^
I will probably have more questions about Jitter and jit.gl.multiple soon…
Thanks again 