Considering a patients age as a potential modifier for coverage would be handy when building a table. An example would be sealants are in fact covered at %100 percent but only until 16, it would be nice for the estimate to accurately show non covered if an adult had a sealant placed. A slightly more programmatically advanced example might be bitewings are covered twice a year until age 18 and then once a year 18 and up. Of course, there are workarounds like making 2 employer plans one for age 0-17 and another 18-and up (For the same group) which I have done, and as long as you remember to swap it on their 18th birthday it works well.
Another thing that might be nice is being able to estimate is a Maximum Allowable Charge and a PPO network at the same time. For example, we are in Network with Delta Dental Premier but not in the PPO so in the event a delta plan is a PPO only (No premier option) our fees should be automatically discount based on the MAC but the patient amount should be increased by the difference between the Premium fee schedule and the PPO.
I'm, sure there are other examples of insurance companies that are doing whacky stuff that come and go and arent probably worth the investment in software money to add when there are other things out there to address. So this falls purely under "Would be nice" lol