Back in my Darwin days, Air North were good at the mini-backtrack thing. We asked them about it and they said (IIRC) that it was a kind of company policy thing to make sure the TORA numbers were exactly right for the intersection departure. After asking a few more pilots it turned out that the figures took into account turning onto the runway directly from the intersection so the backtrack was pretty much unnecessary. It does make a difference, as Keg pointed out, when trying to run things as close as safely possible.
Cheers,
NFR.