DISCLAIMER: I have limited experience with scopes and zeroing - this is a suggestion I thought of after using this optic in-game.
Currently, the "Kashtan" optic for AK-style rifles is not adjustable, and auto-zeroes at 400m. I am suggesting that it be allowed to use adjustable range using the PG UP and PG DN features, like other optics use (ex., ACOG, PSO-1-1, etc.).