It's been suggested many times here and there in other threads. IIRC, the issue when we were playing around with it was that you could get the 1.5 STR mod to a one-handed weapon, but the
Small Stature bonuses also stuck around for some reason, which makes it into more of a buff than just a weapon option.
Alternatively, I've wondered if we could make a custom Small Shield (invisible model with -1 AC) whose only affect would be to add 1/2 the PC's strength mod to their damage. That would provide a workable option until we could actually script something. I wouldn't suggest it as a final option because it's prohibitive to people who could use a one-hander with two hands, but can't use shields. Reminds me of something else I might post later, though.