True...
Yup, if inside the keyhole and in True with LNAV engaged, the only way to select True on the MCP is to select True on Hdg. Ref. In all of the polar operations that I conducted, I actually never had to use select anything on the MCP as we let LNAV carry us along track. The tracks in northern Canada enroute to Russia are straight and there wasn't any reason to do any deviations. There isn't any weather up there to worry about. The Northern Lights were always a treat!
If someone else has experience, I'm all ears.
Thx and safe flight!