I just submitted an edit (Edit #138166215 - MusicBrainz) and too late, realised that there was one more very minot correction needed (An additional colon in track 1 title for consistency with the others). Is there any way of adding this correction short of cancelling and re-entering the entire edit?
I don’t understand classical style, so can’t comment. Colons and brackets look odd to me. I look at that and see many consistency errors. I assume you also missed an (allegro) in track 20 as well? And why is a (Menuet) in 13, but not bracketed in 17? Same with the Andante in 4 and 10. It all looks confusing to me. 
There is no way to queue up two lots of track edits as the second will always be cancelled by the first changing what is being edited.
Often that means that the bracketed ones are not given by the composer’s own instructions, IIRC.
Indeed the brackets are to indicate actual tempos played where none were given on the manuscript. These are as indicated in the CD leaflet notes (albeit with square brackets).
I’ll just redo the entire edit then.
For what it’s worth, using square brackets might even make sense, since that’s what we use in MusicBrainz also for “unofficial names” (see [unknown] or [no label]) 
But certainly not worth redoing the edit a third time for, if you are re-entering it with normal parens already.