The example sentence for まいねん shows reading of まいとし

[Morgawr]

毎年 has two entries with まいとし and まいねん as both are acceptable readings (まいとし is more common though). The one for まいねん shows the same example sentence as まいとし, with the furigana being まいとし.

[stephenmk]

Right now the dictionary / database is structured so that every headword in a given entry is attached to a single unique entry body. So まいとし and まいねん are attached to a single body that cannot be edited independently of either. I've considered making some radical changes to this structure, but there's a lot to consider and it will be no small task.