Welcome to the forum.
Good advice about PM-ing @snipersling.
I haven't used this particular latex, but I'd probably start with a cut 1/4 your draw length and tapered 18 - 12mm for a draw of 32 inches or less and 16 - 10mm for a draw over 36 inches. If you need more speed, you can shorten the overall length by a half-inch or so at a time.
That should get you in the ballpark.