Maybe it is a limitation of CT7 once you have saved the text to speech in the animation. The text is not editable. Therefore my tip is copy your text to speech text into a word processor for your records. If you do need to edit the text just open a new text to speech and paste function and copy and paste from your word processor. The new text to speech will delete automatically the previous saved text. You will also have to change the pitch and speed settings.

I do have a technical question
Where does the text to speech data get stored to when saved? The project file? and would this be accessible or editable?

Being able to re-edit your text would be useful in the next version maybe.

I doubt the text gets saved at all, why would it? It's not a real-time system, it takes the text you type, and convert it to a speech file right then and there. It remains editable until you hit the actual Ok or Apply button.

I use a program called Natural Reader. A text to speech program with various MS voices that you can also add to. Once you write the text, it reads it. Save it. then as ? A wav or other audio formats ......wala then you can use CT or iclone to create your voice for your character from that audio file.....wala!

I also use Morphvox Pro for changing that voice to many different types of voices. Alien, robot, man, woman and so on.....you can change the settings and add sound effects.. Also audacity (free) can also do that by tweaking.

Hope it helps!

MSI GE66 Raider, Intel 10th Gen, I7, SC Turbo to 5.3 GHZ, 240HZ, 64GB 3300 Ram,  2x 1TB M2 SSD Drives, NVIDIA GPU RTX 2070/8GB, 55" Sony 4K Monitor  External data drives total 7 TB. and an AUDIO Studio Recording system.