Agree, 3 yr limit is very challenging. It is even more challenging for a re-applicant like me as one of my significant accomplishment has been rolled off the radar of a 3 yr moving window. Since I cannot mention the ones I wrote about last yr, I've to come up with new experiences for all the essays.
They really try to showcase their value of innovation ( & their 'hand and mind' motto) by asking for a different set and type(action based) of essays than most other schools. I gathered from their info session that unless it is a long term thing that extends into the last 3 yrs, they really do want us to confine us to the last 3 yrs. They know that most students switch careers, so they are least bothered about our career goals.
I say to myself that if I cannot overcome these challenges as a future business leader

, I deserve a ding. Saying this to myself keeps me going