Giulio!! So sorry for the late reply. Thank you so much for putting time into this and figuring it out!!
I just fetched the sculpture with Bela after few days at the Intelligent Instrument Lab, I'm gonna try this right away and let you know.
(FYI, the day of the exhibition I just had to reboot it every now and then when there were no people coming in, it's been quite fine 🙂 )
If you're curious how it looked/sounded, here is a video (doesn't really manage to portrait the most interesting parts, but it gives an idea of what I was working with):
Thanks again for your help, this has been so much fun!! I'm really looking forward to make more weird stuff with Bela. It's just so flexible and powerful, and it's a great incentive to fill in the coding gaps that I have with practical approaches. You're awesome 😃