As I'm trying to source more dots, I realise that maybe my initial system was a bit oversized.

I'm not sure that many places have enough wall surface for two 130cm-long displays (A1 and A2) or the humongous array I planned in the beginning. Look at this :

This is definitely bulky and, I admit, a bit ugly...

Sso I might has to plan for at least two sizes, and mix&match for each installation.

As I'm trying to build an enclosure for A1 and A2, I played with a couple of boards and they are already quite large so maybe a 56-px wide display will qualify for a prototype. That's 9 full-length characters, enough to display some bits of information such as a score or player name... And if it's not wide enough, we can still scroll it !