According to AI, which isn't always 100% accurate...
"NCH Crescendo does not automatically transpose chord symbols when transposing the notes in a score; only the notes are transposed, while the chord symbols remain unchanged and must be manually updated to reflect the new key."
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To change the font size of a Guitar Chord (chord name or diagram) in NCH Crescendo, use the Guitar Chord display settings or the chord's style dialog, adjusting the font size property directly for the selected chord symbol.
Steps to Change Font Size
Use the menu option: go to View > Guitar Chord > Default to change the default display style and font size for all chord marks in the score.
Right-click on the chord mark and select an option like Set Style as Default (or similar) to access display style settings, including font size.
In the style dialog or properties panel, locate the Font Size value and adjust to your desired size (for example, from 6pt to 10pt or 11pt).
Confirm your changes to see them reflected on the score.
Font Style Controls
The style dialog also allows you to change the font family, apply bold/italic/underline, and set color.
Changing these settings ensures that guitar chord symbols and diagrams are easy to read and visually match the rest of your lead sheet."
File suggestions here. The latest (beta) Windows release is here.