conn model 4 multi-board simulation

If a board has a large (120) pin connector and the vendor has a multiline (fractional) version of the model (say 20 pins for middle of the connector) does it make sense to have them generate a complete 120 pin connector model and then in the layout assign that model to the entire connector?

Or should we work with a section of the mode and move it around depending on the signals we want to model (SE or Diff)?

When we use multiboard design links and we use a Mated connector model.  do we assign the model only to 2 of 3 boards (once per conn) or do I assign the same model to board1board2

board1-[mated conn] [mated conn]--board2--[matec conn]  [mated conn]--board3

side view is:

board1                     board3        
[conn]-motherboard(board2)-[conn]

so my signal goes from board1 to board3 via motherboard.