Peplink makes a variety of mobile routers ranging in use cases from Recreational Vehicle to IoT wireless connectivity. The MAX BR1 Mini is a popular lower cost router that can provide backup internet to home networks. It has both WAN and LAN ports, WiFI- as an alternate WAN input, and a cellular radio with 2 SIM card slots. This would provide great value to have sensor and switch connections to HA.
Perhaps try the SNMP integration. The pepware devices support snmp (or so the manual says)