I can tell you they're not Electronics Engineers.

Electronics Engineers are like "we have to design this so that it can handle a power source whose voltage can be between +5% and -20% of what it says on the box" or "assume the resistance of your resistors, the capacitance of your capacitors and the inductance of your inductors can be randomly off by up to 10% plus it changes with temperature".

I switched from Physics to EE at Uni and it went from "these formulas represent the world" to "here is the empirically measured curve of gain vs temperature (were the difference between extremes is over 1000%) of a common transistor you'll have to use".

Maybe it's the area within Engineering or maybe Engineers get taught differently over there, but at least half of my degree was about dealing with how the real world deviates from the "purity" of Mathematical Formulas.

Thats just the difference between a good engineer and a bad engineer. A good engineer designs things around how others are going to use them, and the design with tolerance. They would have known you use 50kg bags, and realized that's what you're going to do.

In my field, we know people are gonna put things together with a hammer if it's too tight, so if it's intentionally a tight fit, we make it so there's no room to swing a hammer

Ask them if they know what SUPAC is and when they say no just shake your head and mumble "fuckin engineers" and never explain it to them.

Scale up post approval changes allow you that 10% variance in non active ingredients.

The amount left over/wasted across the five bags is probably approximately 1.27kg so it all works out

Oh design engineers will make something absolutely functional... In theory, but the people on the manufacturing floor are scratching their head looking at a print for a perfectly hollow sphere with no blends, hole, seams, or affixes made from a single piece of steel going WTF guys? (This is an exaggeration ofc)