Just to reiterate what @PhilipDAth has said already, yes you can use the copper SFP in the WAN ports. We have a number of customers using that setup.
Dont be disheartened, Meraki solutions are great to work with. Understand your venting, we’ve all been there.
Darren OConnor | doconnor@resalire.co.uk
https://www.linkedin.com/in/darrenoconnor/
I'm not an employee of Cisco/Meraki. My posts are based on Meraki best practice and what has worked for me in the field.