We are looking at migrating our enterprise proxy from Squid to NBM 3.8.
Over the years, Squid has been tweaked to resolve issues and add
functionality. I'd like to know if there are comparable settings in NBM.
I have these changes documented in the squid.conf file but am having a hard
time finding equivalent settings in NBM.

In particular, Squid has a "forwarded_for" setting. If set, the setting
includes your system's IP address or name in the HTTP requests it forwards.
By default it looks like this:
If disabled this, it appears as:
X-Forwarded-For: unknown

Is there a similar setting in NBM? If so, where would I check it?