missing features to be able to use OH meaningfully
IMHO openHAB & Cloudron is a good package for users that I understand are private or home users. They install Cloudron on their local network and add the Cloudron instance to their router's firewall as (fritz.box calls it) an exposed host.
OH introduced an admin user in a previous version. Before that, anyone who knows the IP address could manage the entire "Smart Home". But without deeper knowledge, some parts of the status of "your" smart home are visible from the home page.
For example, if you activate the HABot, you can interact with the house.
It's not a drama, feel free to ask me how I cope with 15.82 degrees Celsius in my flat, but you have to be aware of it.
Therefore, it should be possible to add a "secret" level to the application, as in applications like listmonk, or to allow only IP addresses of the local network.
OH (and other smart home applications like Home Assistant) are based on hardware. Zigbee USB sticks, Zwave ... you name it. Is there any plan or idea to support this kind of hardware?
A quick win would be the release of a mqtt companion app like mosquitto. A number of sensors and actuators are able to support the mqtt protocol.