I like Lawrie's method. There are other things to try, too, but I'm probably going to use his way in future.
If I want to hear the chords but see the slashes only, convenient for playing along, then I use invisible chords instead of rests. Instead of visibility "never," try no notehead and stem length zero. Accidentals screw it up, so you can get around that by adding and then cancelling a new key signature, making the k.s. invisible.
Here, staff size is 16, Userfont 1 is Boxmark2, size 14. You may want to pad the beginning of each bar with a couple of preserve width spaces, or put the padding inside the text entry itself.
!NoteWorthyComposerClip(2.0,Single)
|Clef|Type:Treble
|Text|Text:" / "|Font:User1|Pos:-1|Wide:Y
|Chord|Dur:4th|Pos:-3,-1,1|Visibility:Never
|Text|Text:" / "|Font:User1|Pos:-1|Wide:Y
|Chord|Dur:4th|Pos:-2,0,2|Visibility:Never
|Text|Text:" / "|Font:User1|Pos:-1|Wide:Y
|Chord|Dur:4th|Pos:-3z,-1z,1z|Opts:StemLength=0|Visibility:Always
|Note|Dur:4th|Pos:0
|Bar
|Text|Text:" / "|Font:User1|Pos:-1|Wide:Y
|Chord|Dur:4th|Pos:-3,-1,1|Visibility:Never
|Text|Text:" / "|Font:User1|Pos:-1|Wide:Y
|Chord|Dur:4th|Pos:-2,0,2|Visibility:Never
|Text|Text:" / "|Font:User1|Pos:-1|Wide:Y
|Chord|Dur:4th|Pos:-1z,#1z,3z|Opts:StemLength=0|Visibility:Always
|Note|Dur:4th|Pos:0
|Bar
|Text|Text:" / "|Font:User1|Pos:-1|Wide:Y
|Chord|Dur:4th|Pos:-3,-1,1|Visibility:Never
|Text|Text:" / "|Font:User1|Pos:-1|Wide:Y
|Chord|Dur:4th|Pos:-2,0,2|Visibility:Never
|Key|Signature:F#,C#,G#|Visibility:Never
|Text|Text:" / "|Font:User1|Pos:-1|Wide:Y
|Chord|Dur:4th|Pos:-1z,1z,3z|Opts:StemLength=0|Visibility:Always
|Key|Signature:C|Visibility:Never
|Note|Dur:4th|Pos:0
|Bar
|Note|Dur:Whole|Pos:1
!NoteWorthyComposerClip-End