I think the explanation is still the same. Any parameter on a component or “module” run on a “script” automatically takes value from the global parameter. However, when such parameter is set on “normal”, it takes the manual value set for it. Read more about it in the documentation. When a module parameter is set on “script” and the value there is pointing to a parameter available on “global parameter” such as (bit rate, sequence length, time window, sample per bit and etc), it automatically take the value from the “global parameter”.
A bit rate is the one you set on the PRBS either by accessing global parameter bit rate or through “normal” setting. it is possible to be different from the global parameter bit rate if you change it to “normal” and you assign a value. I hope is a bit clear?