Connecting Cell Modems to Cato as Sites over IPSec VPN Connections

I am interested in connecting a fleet of Sierra Wireless RV55 4G LTE Modems to Cato as Sites over IPSec VPN connections.

Does anyone have any experience with something like this?

A few questions--how will devices that are connected to this modem be accessible within Cato? Would they have their own Cato IP addresses or would they maybe only be accessible via port forwarding from the IP the modem picks up?

Devices behind the modem currently receive updates from a set of vendors. It looks like we could setup Remote Port Forwarding to allow these vendors to send traffic from authorized IP addresses and ports to onsite devices. Any known issues or limitations with this?

Also, any bandwidth recommendations for 4G LTE sites with no dedicated users onsite, just  devices sending traffic to a control center?