System and Staff Text - Changing Text

Hi, I have read the handbook and watched the little How To video but do not seem to be able to do what Musescore says it can do.

What I am trying to do;
I am arranging music and as my band often has empty seats I am putting cues in other parts. I am able to highlight the notes and under properties, change them to being a cue, so they appear as small notes. The issue i am having is that able the notes I am trying to add a bracket so I can identify which instrument the cue is from.

At present, I can either;
1. use the 'Add' tab, select 'Text', then select 'Staff Text', this allows me to alter the text and write the insturment, but it does not give the bracket that covers the entire cue.
2. use the 'Pallettes' tab on the left, select 'Text', and then 'Staff----'. This produces the bracket but you cannot change the word 'Staff' that appears.

I would have thought that using both options would give the same result, which it doesn't but also, on the second option, which is the one I am after, should I not be able to change the word 'Staff' as I can in the first option?

Appreciate I might be mixing something obvious but any help would eb greatly appreciated.

Thanks in advance.