the speed modifier causes machines to instantly process instead of doubling speed, this is probably due to the machine definitions multiplying duration by -2.0 instead of 0.5.

also, this probably should be in another thread, but if the speed modifier works as intended, it would not be useful on anything besides the flux manafield. theres no other machine that produces two things out items, fluids, and energy, meaning that using the respective efficiency modifier would effectively bring up production rate as much as the speed modifier does, but without also doubling inputs. i think this can be solved best by nerfing the efficiency modifiers, say, to 1.5x production instead.

i know that multiplying by a decimal cant be done directly for items due to the way modular machinery handles multipliers, but it can be done indirectly by dividing processing time by the decimal (multiplying by 1/the decimal) and also dividing all inputs by the decimal. this does mean actual production at lower input counts will deviate from expected production greatly however, so its not a perfect solution. but at least the fluid and energy efficiency modifiers wont have to use this kinda scuffed multiplier and can have their amount get multiplied directly by a decimal without the results deviating too much from expected values. if nothing else, at least buff the speed modifiers after you fix them so that theres a genuine reason to use them for machines other than flux manafield.