Thanks for your work on the Custom Route Calculator.
Your options are Min Distance and other stuff.
Kindly note that Min Distance is only really a ‘thing’ for sectors <2 hours. Beyond that, the winds are a major factor.
You should really offer a “Min Time” option to factor in the winds aloft.
I’ll also mention your Mid Distance seems to use a flat earth. A quick CYHZ-CYYC at Min Distance generated a route (KELNO MOWND MLT JUNIS YXZ TRUDY UDBOX GUDOG BIRKO BIRKO6) which is +2.5% over GC. Your Min Distance went up to +3.5% with a wacky route using airways [not a thing on this continent or in other FRA !!!] (KELNO Q806 SAVEX BEMOG Q919 OMVEG Q940 KOBID Q831 DURUR Q828 VINKO ILADA BIRKO6)
A perfectly valid route would be KELNO UDPAV BIRKO6 AT +0.8%
Appreciate your continued work on this 