I combined 1 raspberry pi5, 2 uno r4s, 1 uno r3, and my laptop on to one end to end communication plane. I'm using HiveMQ MQTT serverless, and a MariaDB webhosted back end and a java/php front end for browser viewing. All Secured and works better than expected. Started calling it AXICOMS you can read more on my website; link below.
If anyone has an experience with this I'd love to chat. Thanks