Hi @redsector , I think you are meaning a kind of WAN breakout switch? Meraki switches just need a way to get to the internet for dashboard management on its Logical Management IP. You can just connect a physical port to the LAN of the site for dashboard access and prune VLAN's accordingly to avoid bridging networks.
In the case that you are connecting internet services if the switch can get an IP on the CE/PE subnet i.e. ISP provides a /29 then this can work for management. In the case you are using MPLS the same applies provided you can get to the internet on your MPLS network.
We do have the concept of an Alternative Management Interface which is a logical (not physical) interface for sending RADIUS/SNMP and Syslog messages via an alternative path - but is only supported on MS210 and above
https://documentation.meraki.com/MS/Other_Topics/Alternate_Management_Interface_on_MS_Devices