Setting it to 0 isn't necessary, though - Due to how the structure of an item drop is handled: "(item name), minlv, maxlv, ratelow, ratehigh". So for instance, a 1/99 Gigush between levels 1-5 would be: {"Gigush", 1, 5, 1, 99},
(formatted into an array).
To be specific, this exact line: {"aileron frame", 51, 79,1, 30},
is featured twice in S.D.UR.F's lua, yet other items are only featured once and function fine.
Both ways one of those conditions would end up false normally and that would likely cancel the drop.