Since the description of ${name}_limits did not mention anything about the default value I decided to improve it. Also, I documented the ${name}_login_class variable, which seems to be used by ${name}_limits only.
${name}_limits has been introduced in D14015.
I wonder if it's worth printing the random seed somewhere, or even using a fixed seed. If this triggers a bug it may end up being nondeterministic (and thus difficult to debug).