Personally I think you are doing the right thing by creatig a custom "fact".
In GEDCOM terms these are actually called "Attributes" and are defined just with a FACT tag and a dscription. When I use custom facts I use them in the same way I use the OCCUpation tag/fact/attribute. Most of my relatives were either farmers, sailors or potters all family inherited occupations, so I connect these to a lot of people. A tag such as "Civil War Casualty" would not be defined with a date or place displayed.
Once created it is available to add to every person and really only a click away from being added to everyone that needs that fact.