Can someone take a picture of the TV when Caller ID is on the screen?
I personally wouldn't let one small feature of the H3 be a deal breaker if all the other benefits and features are what you like/need. Who knows, they may improve it soon. It is kind of small to be honest, believe Dish is simply trying to balance this with people who would complain that it's too big and intrusive when watching TV if they enlarged it.
IMO, if you want caller ID on then you accept the fact it will temporarily be on screen for a short while or until you press the select button. It should be formatted properly and also enlarged.
Another option if you really do like to have caller ID announced, look at getting a phone system or answering machine that speaks caller ID. I understand that if the Hopper promotes a feature like on screen caller ID it should be easily viewable. Dish never really seems to understand the importance of usability when it comes to certain on screen menus/texts or the guide for people with smaller TVs or vision issues. A simple option would to keep caller ID like this as default and then offer an option to make this much larger to accommodate any issues or preferences.
This is a 42" screen, showing about 2/3 of the screen width: