For example, if you set "Other Debuffs" to 0% size, miscellaneous debuffs are visible at their default size. Setting it to 1% makes them tiny.

Here is a very crude fix you could implement. I'm sure there is a much better way to do it, but this is the functionality it should have:

Line 1404 of BigDebuffs.lua

if debuffFrame.baseSize < 1 then
	debuffFrame:SetAlpha(0)
else
	debuffFrame:SetAlpha(1)
	debuffFrame:SetSize(debuffFrame.baseSize, debuffFrame.baseSize);
end