If I am going staccato. Flat or curved trigger. Does it really matter?
I don't think it matters.
The most important thing for most people really is just getting the shortest one you can. I can't recall seeing anyone, regardless of hand size or finger length, do better with longer triggers. I like the "feel" of longer triggers, but that's a siren's song if there ever was one - it tends to induce shot groupings left, or low and left. There are videos from some top makers that tell you how to fit the trigger to your finger length by measurement, but, again, I just don't think that usually matches up with reality for what produces the best performance.
I've had both flat and curved, and while flat seems to "feel" better, I can say it definitely doesn't shoot better, at least not for me. It's a wash. I just picked up the shortest flat and the shortest curved I could for my Staccato C, but only did so to be able to personally see which one would actually be shortest. Often, that's the curved. But I'm thinking about trying what Form seems to do, in shortening one of them even further.
That said, there is a theory out there, that the more curved you can get a trigger, the better, because it puts the pad of your finger into the curve more consistently. There may be something to it, but I suspect you'd probably have to be at a truly elite level of shooting for there to be any measurable difference at all. And, that it probably wouldn't be in any kind of action/practical pistol shooting. More of a precision rifle thing, if there's any merit at all.