With my current bow setup, my arrow kept slipping off the factory arrow aligner and falling off the shelf as pulled back. This has higher sides & prevents this issue. I have a Darton bow and this works on the shelf with some strong double-sided tape. I have included the .step file if you need to modify it for your bow model.

I used TPU filament to provide the necessary flexibility for the part to conform to the shelf. To enhance rigidity and ensure the arrow remains securely in place, I recommend using a high infill percentage during printing.