MOD files are "dummy" PLNs that do not store unused attributes. The attributes that "show" in a MOD file are the attributes of the previously opened file.
Import Pen Sets via the Attribute Manager, although your MOD will read the attributes of the host file, so it's not necessary to import them into the MOD.
MacBook Pro Apple M2 Max, 96 GB of RAM
AC27 US (5003) on Mac OS Ventura 13.6.2
Started on AC4.0 in 91/92/93; full-time user since AC8.1 in 2004