How "Offcet Edge Slide" calculate length for Factor value with Even option

I need a help to find how Factor value is calculated with Even option turned on.
What sliding edge is used to calculate length for Factor value?

I need it to write a script to slide on absolute length.

1 Like

We used to create a separate 1meter plane that contains active edge so factor of all ofsetted edges made with this operator became absolute since in that case they are counted from 1meter.

Not sure if script is a good idea, this is quite basic precise modeling demand that better be solved at the core level.