Possible solution: Update value type for number of applied bonuses. Currently it uses "byte" value type.
For example: You have 1 tool for bonus output (computer), it will be applied fine until you reach 127 number of workers at one line, at 128 it will overflow, which will be ignored in formula (counted as 0 probably). If you have 2 bonuses (computer and electricity for example), overflow will be at 64 workers and so on.
For example: You have 1 tool for bonus output (computer), it will be applied fine until you reach 127 number of workers at one line, at 128 it will overflow, which will be ignored in formula (counted as 0 probably). If you have 2 bonuses (computer and electricity for example), overflow will be at 64 workers and so on.