EOC and Orion Sites on Different Versions

We are deploying a standard Orion (NPM, NCM, UDT, IPAM, SEM, SAM, and Engineer's Toolkit.) to +12 sites and connecting them to our EOC.  All installations are 2019.4.  EOC is new for us and we've not built out many dashboards, reports, alerts, etc.  We're about half way through and considering upgrading our EOC to 2020.2 and continue our deployment of Orion 2019.4 to the remaining sites and then have the sites upgrade after the project.  That way installation/configuration process and documentation is standard and we don't have to pause the project to update process/documentation, retrain our installer, etc.  For the sites, we've standardized on NPM, NCM, UDT, IPAM, SEM, SAM, and Engineer's Toolkit.

Any concerns or caveats?