Support on Ignition architecture (Edge - Remote tags - Local fallback)

I'm trying to set up a system using Ignition and i would like some help on Architecture and Configuration.

The network i would like to create should be similar to the one pictured below:

The main functionalities i would like to achieve:

  1. Local fallback: The vision client on the industrial pc will mainly display the project in the main gateway and in case of miss signal it will verge to the simplified project present in the local edge gateway.
    I configured the option "Local Client fallback" on my edge gateway and it worked fine when i tested.

  2. Remote tag provider: I was able to configure a OPC-UA connection to my Allen Bradley PLC and retrieve all the variables as Tags with no problem.
    I would like these tags to be avaiable to both gateways, how should i procede?
    Is it better to configure OPC UA connection on both Gateways or to set up Remote Tags ? (The steps to implemnent the second options are not clear to me as it seems that before using "Remote tags" i should configure also a Gateway network. I do not have purchased EAM module)

  3. Read/Write .txt files: I already tested the functionality in scripts using both gateway and it worked fine (In local folder). Is there any limitation in the case of a remote shared folder?

Are there any considerations on the way i'm building the architecure? Am i missing something?
I do not have EAM module, is it necessary for this type of application?