Hi,
I work for a nonprofit that is beginning the process of migrating to Laminas.
Does anyone know if there any nonprofits organizations that’ve made the migration from a legacy system to Laminas? If so, we have a few questions and would love to connect!
Thanks
Welcome to the forums! 
It doesn’t matter here if you’re non-profit or not. Ask your questions without any restriction.
It is an important information what you mean with “legacy system”. Do you have some version numbers?
In documentation you will find a chapter for migration to Laminas. Maybe this will help for a start.