Lower Temp Hop Stand/IBU Calculations

I am very new to BS and to all-grain brewing in general.  In many of my recipes, I include a 30-40 minute hop stand once the wort has cooled to below 170 degrees.  In planning my recipes, however, I have not found a way to adjust BS's calculations of IBUs for this sort of lower temp hop stand.  BS appears to treat such additions as either flameout ones or late boil additions, which makes the IBU calculation shoot way up even though such additions typically do not add much bitterness.  Is there a way to add such lower temp additions and get a more accurate calculation of IBU?

Right now there is not way to adjust the starting temperature for the whirlpool additions.  What I have done to mimic my process is to adjust the 'steep/whirlpool util factor' which is found under 'options' >> 'bitterness' down to what my taste buds estimate the bitterness to be from these additions.  The default is 50% figuring on a 90C (194F) addition of whirlpool hops.  I have mine set down to 30% and it seems to be much closer what my system produces.

Thanks!  I'll give that a try.