I understand there may be technical difficulties in reducing the minimum, but we should consider it a flaw if we have a four-letter minimum, or even a three-letter or two-letter minimum.
I'd also consider the error message given when searching for short words a Bad Idea.
[!! SYNTAX ERROR: the word 'the' is too short, the index requires at least 4 characters] AND "cunctuator"
I think it would be better if words shorter than four letters (or stop words) were ignored, and a more polite error given if it can't search.
Dragon Dave.