Projects for serveral water treatment plants

I am investigating the possibility of using Ignition with several water treatment plants within a corporate WAN

I want to use a central gateway with AEM (controller) and several connected gateways (agents). A gateway is placed at each water treatment plant, and one AEM controller centrally in the IT department

Operators want to be able to monitor all water treatment plants from a central project, all views, alarms, history, etc.

History must be stored 1 month locally and 5 years centrally.

Alarm notification must be handled centrally, but in the event of a communication failure, the local node must handle alarm notification

Rights for users must be stored centrally and affect all nodes

A local HMI is placed at each water treatment plant for the possibility of controlling the plant in the event of a communication failure.
When a view is changed centrally, it should also have an impact on the local HMI (perspective)

In what way should the system be built? I want to use perspective

Option 1

I thought about building a project for each water treatment plant and then build a simple project centrally that via tree menu can link URL to a local project, the problem is that then login is required for each unit in the tree menu (annoying for operators), but maybe solvable with to use
IdP (Active Directory Federation Services)?

#Options 2
Retrieves tags from local gateways through gateway connections. Then build a large project that covers all water treatment plant and run it on the AEM gateway. Views are updated locally via EAM updates

#Option 3?

I’m new to Ignition and it’s very advanced so there are probably several ways to build, but am I on the right track?

English is not my native language if there are any spelling mistakes