Works on 2.0. Made possible with the new read all belt contents option.
Circuit acts as randomizer and limiter for how much each science pack put in the belt.
Beware of overcrowding the belt, in the original form with 115 belts, there are 115x4 = 460 slots. So if you unlocked all 12 science pack 35 per pack in belt would be a reasonable number.
Feel free to expand the belt or labs to your liking, it's a pretty simple design.