When I select Display→Custom Reticles, I see reticles boundary according to selected telescope focal length. I want see reticle boundaries for different focal lengths at one time very often. This is typical situation for Main camera and Guide Camera. You could specify Telescope in the Custom reticles window. If a telescope is specified we use focal length of this telescope. If not specified - assume the main telescope (specified for the FOV chart).

Implemented. Added a Telescope chooser for Imager type custom reticles.