Omada Cloud Essentials exists entirely in the cloud, offering remote management and monitoring via the Omada App or web browser. It eliminates the need for a local hardware controller or software controller installation. While the management platform is cloud-based, you can still use the Omada App or a Discovery Utility for initial local adoption or to find the IP address of devices on your network.
But when come to limitation, free thing come with a lot of limitation. You cannot login to the local gateway when the internet is off unless you reset the gateway to become standalone mode then joint it back to cloud. It can be a nightmare to troubleshoot. So it was better to get a OC hardware controller.
VPN it only support wireguard VPN in cloud essential mode. it was lack of support how to configure it. you need to google and it was not straight forward.
Either way you can just go for reyee product which is have local controller on every equipment (hybrid). Hope they can improve it.