Indentation within function arguments isn't configurable

Currently if you are in the middle of a function call, pressing Enter has fairly odd results (seems to depend on function length).

Before pressing Enter:

        my_function_call(^foo, bar);

After:

        my_function_call(
                    ^foo, bar);

(where ^ is the cursor)

The indentation level here isn't configurable, and seems to use some smart logic which I mostly end up manually adjusting.

It would be good if there was an option to select a fixed indent level for multi line function arguments. (or align with the opening parens)