Customize response encoder and service options for specified API

[septemhill]

Do we have any way to customize the encoder and service options for specified API in MakeHTTPHandler ?
Because all of APIs use the same encoder and service options from MakeHTTPHandler, but I need to use
different encoder for some of them.

But the problem is, after I re-generate the code, the part be replaced again and again.
So I want to ask do we have way to avoid this ? thanks !