In my review of Kyvol Cybovac S31 LDS smart robot vacuum cleaner, I noted that app permissions meant both the map of your house and GPS coordinates may be sent to the cloud. But it was pointed out to me that earlier LDS robot vacuum cleaners from Roborock/Xiaomi were supported by Valetudo project that removes the need to connect to the cloud, and implements a mobile-friendly web interface as well as MQTT support for integration with Home Assistant or Node-RED.
The project is not a custom firmware for the robots, and instead, the stock firmware is patched with