I would like to be able to enable and disable input controls based on the values of other controls. I don’t see any built in way of doing that. If I could add html to the inputs as they are rendered, I could add some javascript to do it, but I don’t see any way of doing that. Is there a way to add “extra html” to entities as they are rendered?
The default UI doesn’t have this ability, but you should be able to do it with Lovelace or using the custom-ui mod.