Seriously awesome work on this post, thanks for putting it together. This inspired me to play around with zram and I had a LOT of trouble so I wanted to share my solution in case anyone else has issues.

It installed without issue on Ubuntu 16.04 but simply wouldn't start, responding with the less than helpful zram-config.service: Failed with result 'exit-code'.

To spare anyone the literal hours of troubleshooting I spent on this, the solution is pretty simple:

apt-get -y install linux-image-generic

Run this first and then follow this post from the top.