Background

The MCO does not reap any old rendered machineconfigs. Each time a user or controller applies a new machineconfig, there are new rendered configs for each affected machineconfigpool. Over time, this leads to a very large number of rendered configs which are a UX annoyance but also could possibly contribute to space and performance issues with etcd. 

Goals (aka. expected user outcomes)

Administrators should have a simple way to set a maximum number of rendered configs to maintain, but there should also be a minimum set as there are many cases where support or engineering needs to be able to look back at previous configs.