We are considering MTOM for web services network. Looking for options
for disabling internal base64 encoding in the .NET MTOM
implementation. We are dealing with very large payload as attachments
in our web services. Base64 encoding and decoding such document is
prohibitively resource intensive. As these large messages will not be
digitally signed (the attachment itself can be signed), we would like
to be able to programmatically disable Base64 encoding/decoding from
both client and server as necessary.

Is there a way to do this that is inter-operable with with other implementations.