I am currently running 1 main site (550mbs/50mbs static external IP) and 2 smaller locations (both using 4g lte unfortunately utilizing CGNAT which causes several problems) on Omada hardware (intending to increase this number to potentially 10) currently each site has its own OC200 controller and ER605 vpn router, i'd like to know if its possible to create a site to site vpn link from the smaller locations to the main location and route all data over the VPN link all controlled and managed by the Omada system.

Looking on the OC200 interface it appears like we should only have a single OC200 and that should manage all the sites and ER605's centrally but if i do that i loose the ability to log problem/issues and manage everything locally at the smaller sites if the internet connection is down (which happens frequently). I also don't see how i can have multiple ER605's managed by a single OC200 ive tried sever times to adopt them but it would only allow me to adopt 1 at at time and would not let me adopt a 2nd one.