Details
The line font of PMI custom symbol is not reflected in drafting though it works as expected in modeling when we set "Annotation Preferences" to "Use Definition" in customer symbol dialog.
Solution
Additionally "Use PMI settings" option needs to be selected for "PMI Custom Symbol settings"
Location of this setting:
Customer Defaults->Drafting->General/Setup->Workflow(tab)->Inherited PMI
Hardware/Software Configuration
Platform: INTL64
OS: windows
OS Version: 1064
Product: NX
Application: PMI
Version: V12.0.2
Function: INHERIT_TO_DRAW
Ref: 002-8513584