Process reaping and signal forwarding are solved by using tini. You can call if from inside the container, by installing it and then changing the entrypoint/cmd. You can also specify it in your docker run/docker create command by adding "--init"
I haven't seen the phusion base images in production in almost a year. Usually when an organization gets more experience in building images, they use better solutions then phusion images.
tldr
Don't use Phusion base images. If you need ssh and logrotate and etc, use lxd or a vm.