If you want to add additional cells for one of the functions, place the extracted subckt in
magic/subckt/vsclib013

Then edit the appropriate allcpedit and allfunccpedit files in order to add this new cell to the list to be characterised. For example, for a new mxi2, edit mxi2/allcpedit and mxi2/allfunccpedit. Make sure that the drive strength is compatible with the existing cells. An x2 cell has a P transistor width of about 25λ.

Then run allcpedit and allfunccpedit to recreate the CIR Spice simulation files for all the cells. Running allmxi2 will characterise this new list of cells.
$ ./allcpedit
$ ./allfunccpedit
$ ./allmxi2

The allfunccpedit creates a set of CIR files which test the functionality of the cell. These are useful if an unusual transistor configuration is being tested. These functionality simulations are not run from a script, but interactively in winspice.