I just looked and BG publishes nothing about their specs for building your own tape.
You can still do it with archers Advantage. Put a blank tape on your sight and sight your moveable pin dead on at its fixed position, so if 40 is your slider sight 40 in and make a mark on your tape and put the indicator there.
Move sight to 80 or 90 and sight in and mark the tape.
Move sight to 30 and do the same snark the tape.
Put all your specs into Archers Advantage. When you go to sight in tab, select Inch. 1st mark will be 30 and that will be 0,. Then measure 30 to 90 yard mark. It will be around 1.2". Your second Mark will be your long one, 80 or 90. Enter your measured tape distance in that box. Then print a tape and tape it to a table. Pull your old tape off and compare them side by side. If your printed tape matches your hand made one you are done. If it doesn't, just get increasing or decreasing the measurement until it does.
If that doesn't make sense, call me when you are in front of you computer and I will walk you through it. Or call about any of these issues. Tapes are not difficult once you learn how to manipulate the programs to make them perfect.
Doug 916-607-1222