This is simply a math problem.
Assuming that content is available instantly (e.g. you’re playing it back from the AutoResponder) then the only delay is controlled by request-trickle-delay and response-trickle-delay flags.
There are 1000 milliseconds per second.
So, if you want to gate the connection to 1 megabyte per second, you would use a delay of 1 ms. If you want to gate it to 512 kilobyte per second, then use a delay of 2 ms. For 256 kilobytes per second, use a delay of 4 ms.
Keep in mind that bandwidth is often measured in bits per second rather than bytes per second. So if your goal is to measure things in bits-per-second, then multiply each value by 8.