In general, it is not recommended to eat unhatched incubated chicken eggs, even if they appear to be infertile or if all the other eggs have hatched. There are several reasons for this:

1. Potential Contamination: Unhatched eggs may contain bacteria or other pathogens that could pose a risk to human health if consumed. Even if the egg appears to be infertile, there is still a possibility of contamination during the incubation process or from the environment.

2. Unknown Development: It can be difficult to determine whether an unhatched egg is truly infertile or if it contains a developing embryo that did not survive. Without proper examination and knowledge of the egg's development, consuming it could pose a risk.

3. Regulatory Concerns: In many regions, there are regulations and guidelines regarding the consumption of unhatched eggs, particularly those that have been part of an incubation process. These regulations are in place to protect consumers from potential health risks associated with consuming unhatched eggs.

4. Ethical Considerations: Eating unhatched eggs, especially those that may contain developing embryos, raises ethical concerns for some people. It may be viewed as disrespectful to the potential life within the egg or as a violation of animal welfare principles.

If you are unsure about the safety or suitability of an unhatched incubated chicken egg, it is best to err on the side of caution and refrain from consuming it.