Is it Possible to apply rate limit for Sender Dependent Outgoing IP Address setup?

Dear folks,

I am interested in the article here: https://www.virtualmin.com/documentation/email/dependent. And as a matter of fact has successfully followed the article and done probing by myself on my machine which has worked.

However, I noticed that when sender_dependent_default_transport_maps is enabled, then Postfix ignores the transport_maps:/hash/etc/postfix/transport file where I usually put rate limiting such as mentioned in this article: http://steam.io/2013/04/01/postfix-rate-limiting/.

I am wondering how to enable both sender_dependent_default_transport_maps and transport_maps as well. Please help.

Thank you!