I like your work around and I usually try to have a way to deal with nulls. Here is a creative thought for you to solve your problem.
When your are placing your field in your Word template, use a formula. In this case an if statement. If the value is not null than, show your field. the alternate in my case is to show Test. You can replace test with space n/a or whatever character you want.
Surgeon is the name of a field in my data model and this only produces output when it is selected.
=if([Surgeon] <> null(), [Surgeon],'Test')
If you have 4 fields, you can create 4 formulas
Hope that helps or at least gets you thinking to find your answer.