D316 14m: 2.11
D316 15.5m: 2.41
Here are the curves for both of those and XTOL:
Do you think it's possible to match XTOL's curve? If not, imagine a curve halfway between those two corresponding to about 14.75 minutes. It's not what XTOL would produce, but would be similar to Tri-X. Maybe that would be acceptable?