There is really no way to know that. There are a lot of variables that go into deciding the workload:knowledge you will have for a particular desired retention value. For example, you might spend too much time with (re)learning cards compared to review cards. This means, if you decrease the desired retention your workload (and workload:knowledge) will rise quickly because of the higher number of (re)learning cards. If all things being equal, you were spending less time with (re)learning cards then the desired retention value CMRR (compute minimum…) gives you will probably be lesser.
This is only an example to illustrate how something might affect the feature and doesn’t mean I am giving you prescriptions for what you should be doing. Also, take this with a grain of salt because there might be some things I haven’t taken into account.