Hey! I recently had a go at writing my first integration! I hope to add a remote entity to it still to send CEC commands to both inputs and outputs, but it seems to be working well for my 4x4 matrix
Link: https://github.com/taysuus/hass-orei_matrix
I also made a quick feature for the tile card to show a select dropdown for the source, this helps my dashboard with this integration https://github.com/taysuus/source-select-feature
If anyone else has these matrices, I’d love your feedback! 