[crote]

It could also be programmed during production. Clearly the LED manufacturer has the equipment to do wire bonding, so why not use the occasion to program it too?

It'd be a bit comparable to the test and assembly process of the WS2812B, see [0] @ 2:30 or 6:10.

[0]: https://www.youtube.com/watch?v=pMjhJ9kcaU4

[joezydeco]

Anything is possible, I suppose, but burning EEPROM is an order of magnitude slower than anything these robots are doing.

[crote]

I'm not too worried about that. The slowest part of EEPROM & flash operation is erasing an already-used page - and that's not the case here.

Chips like these only have 1kB of flash - I'd be surprised if you couldn't program them in less than 100ms.