This is what I get:

I would not call these parentheses “huge”.

Anyway, the Chord Tool is a very powerful tool.

You can have the parentheses in any font, in any size.

I WOULD call these huge:

And as far as I can determine, I would have to correct each chord type individually, as all chords with parentheses look like this. The offending characters are Maestro 24 plain.

In Document Options: Symbol: Finale Copyist Text Ext 16 plain; Suffix - Times New Roman 11 plain; Alteration: Arial 10 plain.

You can not change already existing chord suffixes via the Document Options (in the Document Options this fact is shown with the * symbol).

All new suffixes created after the font change will get the fonts chosen in the Document Options.

Load the Arial font chord suffix library (File menu > Load Library…)

For chords already entered in the score, delete the suffix from the Chord Suffix Selection.

Finale will offer the option of replacing the suffix with another suffix.

Pick the Arial suffix you just loaded.

Repeat these steps for each suffix.

(- or create your own suffixes, and save them as a library).

Perhaps I should be more clear: EVERY SINGLE PARENTHESIS, FLAT AND SHARP IN THE ARIAL CHORD LIBRARY IS HUGE.

I have tried reloading the library. I am looking for a helpful solution which won't involve creating an entire library, and won't have me "fixing" every chord symbol I need to use. And yes, I am aware of the fact that I cannot change existing suffixes in Document Options.

For me the Arial chord suffix library does not display the huge characters shown in your screen shot.

Possibly it is because I am still on Finale v26.

Do you have any Finale v26 documents with the Arial chord suffixes?

I suspect that they will display correctly when opened in v27.

If you still have Finale 26 or 25 on your computer, see if opening the document there is correct.

I suspect another SMuFL botch.

I don't have any Fin26 documents with Arial chords. I do have Fin26 on my system, and opening an older document and loading the Arial chord library gives me a file with characters in their correct size. Opening a document in Fin26 which was created in Fin27 produces a file with all sorts of weird stuff - completely unusable. Loading the Arial chord library into this document - still in Win26 - gives me chords with outsize parentheses, flats and sharps.

It sounds like you have found a bug.

I suggest that you report your findings to the folks at MakeMusic.

You can use the hyperlink {Submit a request} at the top.

Already did that.