When adding LWN to a vessel it auto defaults to 6" outside projection, if this is changed the flange jumps to the OAL length in the equipment library and cant be modified beyond that. Is there a solution to fix this?

I believe its reading the LWN flange from the data table values.

Perhaps you would get he desired results with a slip on flange ?

Rather than using the Nozzle Type: Standard. Have a look at using the LWN from the FVC Nozzle Type. Here you can set it up to use catalog dimensions or Actual dimensions (your dimensions).

I have had better success with these components rather than the standard which has limitations.

If I remember correctly, I think there was an issue where CADWorx had applied Nut Stop and Nut Relief dimensions to this item that needed to be tweeked in the master catalog as these do requirements do not apply to LWN's.