the "bonus items" kinda work both ways, they can both round up your item value and round down, take for example:
300 * 0.125 (12.5%) = 37.5, those 300 items would be worth 37 and a half items, so there's a 50% chance you get "only" 37 items, or boosted to 38 items,
ofc if you had 600 items you'd land on 75 which is a round number.
one way the mod "could have worked" is counting up, like 8 * 0.125 = 1 item, then the mod could just wait until a full number got reached, but what if you had 9 input items and the inventory is full, there'd be no space and it would be annoying to halt the machine or spill items on the ground.
or what if the input ratio of items to the quality percentage never even hits a full number? there are a lot of edge cases to consider.
so in the end for my own sanity i choose to just use the remainder as a chance to round up or down, its not exactly creating new items its just that the decimal point becomes the chance aspect, like quality kinda inheritly is.
i "could" store the remaining fractions as script data but that would just be a little nightmare and also unfair if you were to deconstruct it whilst there were still some percentage points inside.
if you have any clever ideas or things that come to mind you're free to voice them, whilst i could add an option to "never round up" (thus giving you a net loss) i don't really think that would be a sensible approach, ofc to get the lowest chance of the randomness making an impact its best to stuff the machine full of a single item and a single quality since the more items get inputted the higher the base guarantee and the least amount of random influwence.
oh yes i made a lot of space exploration addons and i look forward to porting some of them, k2 might very soon be on the horizon so that's one that will get a port for sure.