If there is not report button then you assume you can't report it, regardless of the reason.
What I do for my plugin (yes, I do have a plugin similar to this -.-) is to change the report image for a different one (1 extra template, similar to how the new/closed thread button change), maybe that is the best option if you don't want to just remove the button (users can empty the template if they don't want to show the button).
What I do for my plugin (yes, I do have a plugin similar to this -.-) is to change the report image for a different one (1 extra template, similar to how the new/closed thread button change), maybe that is the best option if you don't want to just remove the button (users can empty the template if they don't want to show the button).