I suppose you could set a default value of something like 9999999 (which falls within the Validation range) so that the user is _kinda_ forced to enter the real qty, but if they're skipping over a 0 qty, it's entirely possible they'll skip that bogus qty as well. I did some quick tinkering and entered an invalid default value on that field via DFDM, but it appears it doesn't really help unless you actually enter something into the qty field.