Instead of silicone you could use Sugru. I don't have a great picture, but you can see belowe how is smoothen the hdmi connectors.

I thought I would share, as I was really glad I found this solution.

https://www.mupload.nl/img/znajfy5t9wrkp.13.51.jpeg

Is there any update regarding this development? Seems really nice. I am still looking for the best way to make nice back bottons.