I have created a small project for reading the instant readout (bluetooth) and pushing this to homeassistant via mqtt. It requires and esp32 board with bluetooth support.
I can easily add more hardware board options so raise an issue on github for that. Any esp32 with ble support should work.
I have so far added support for the devices i have but can add support for more devices if i can get some sample data
Project can be found here; GitHub - mp-se/victron-receiver: Victron Instant Readout receiver for Home Assistant