All right, I think I anderstood !
So If I setup 12 strips (BXEB-L1120Z-30E4000-C-B3 in particular) with 1pcs HLG-320, each strips would be working at 26,6Watts (to get 320Watt total)
Is it correct? And is it efficient for a 1.2x1.2m?
If needed, I setup again the same installation to double...