Okay, I'll add the HDMI input to my to do list.
If you're doing all the on-stage cabling yourself, the sound person doesn't really need the inputs on the stage plot to see how to set things up. But if you add the inputs to the plot, the sound person can see how the inputs match up to the members of the band and you wouldn't need to include the band member names in the input labels.
You almost don't need a stage plot since you're providing most of the equipment and doing most of the setup yourself. But I think I would recommend adding a note that says something like "We'll set up all the inputs on stage and simply need a 16-channel snake placed near our mixer to feed our inputs to the FOH." I could possibly add an icon for the snake, but this could be confusing for other bands because normally it's up to the venue to get the inputs to the performers and the band doesn't need to specify how that is done. So I feel like just a note clarifying the division of labor would be best.