Is it important for a nurse informaticist to have experience in multiple nursing units? Not really.
Look at companies like Cerner or Epic---they hire people who implement their applications without having any nursing experience at all.
I did nursing for 8 years, and floated to many units, except the OR. What was my first application to implement? Yep, an OR application and in my first meeting I had no idea what the hell they were talking about. I thought I knew nursing, but yep, had never really stepped into the OR, but on my 2nd day, I met with the OR nurses and they walked me through their workflow. There are always things to learn, no doubt, but is no rocket science to figure out the workflow of any nursing department.
what matters your nursing experience...you can learn any other nursing workflow in days, if not hours. It is not that hard.
I've implemented many departments that I had zero experience in, but learned the workflows without a problem. So no, don't worry about having experience in multiple nursing units..sure, it helps, but believe me, thousands of informaticists out there implementing departments they had never worked in.