Commas accompanying a "which ..." clause inside parentheses

Here is a sample sentence:

The output of Tim's method (and the methods of Mark and Brad, which leverage Tim's method) is much greater than that of Tom's method.

Is this correct? Do I need a second comma? If so, where would I put it? If I removed the parentheses, it seems that there should be a comma after "Tim's method" to separate the clause "which leverage Tim's method" from the rest of the sentence.

Someone had suggested to me that I should remove the comma before "which" and replace "which" with "that", but I don't feel that the result would have the same meaning as the sentence I have above.

Thanks!

(Note: I did take a look at everything I could find by searching "commas inside parentheses", including this post. I don't feel like this post covers the same problem that I have here and, if it does, it is not obvious to me.)

Answer

The comma after an adverbial (nested) phrase signals that the parsing returns to the previous (less deep) level of nesting. You wouldn't put a comma before a period or a semicolon, nor would you put one before a closing parenthesis. Those symbols signal 'popping' to a higher level (to the top, for a period), so they supersede what the comma would do.