Hi,
I found some internal discussion that indicates that BRM / Oracle Infranet it is a C based application which relies on a LDAP and Oracle Db. I see it is mentioned here too:
https://blogs.oracle.com/yani/entry/a_brief_introduction_to_brm_and_architecture
"All functions that give life to BRM are in this layer coded in C language called Opcodes (System Processes in the image)"
I suggest you to contact Oracle Support for clarification on this.
Maybe you can use logreader extension to create metrics based on logs, here are some examples or references:
logreader_package.zip
use the epagent, or you might also want to contact, Professional/CA Service Team, as they can implement/develop an extension or customization for you.
Regards,
Sergio