Certainly possible from inside the FamilyGroup and PersonGroup class. Not real clear on what “years” you want to display. Probably not something I will focus on any time soon.
But, at some point it wouldn’t take that much to allow the Name to include “\n” or some other chars to specify a new line, or even potentially allow for some configurable notion of fields to show in addition to name. For the Presidents data set I have wanted to show Occupation in the models so its easy to see who actually was the President and what number they were. Similarly for the English Royal Family data set I wanted to include who was the King/Queen in the model.
For the direction I’m heading for time, what I want is to have a notion of a time line. As a slider above the model that has years and moving back and forth would shift the avatars to show people appropriately based on the year selected in the slider. This assumes you have a yearly avatar of the people displayed. Not likely to work for the past very well but could be done for the future. Some day I will put together as many pictures as I can for my family to get close to a yearly photo and make a prototype to see if I like it as much as I think I will. What I really want for avatars is full 3D models not just photos but thats a hole different set of issue that is possible but probably not real practical yet for many reasons.