[Feature request] Overlay for fast typers (overlay shows current/last written word)

This is a design proposal for a word-level overlay on the keyboard, and the issue names no files, tests or entry points. Before any code, a maintainer needs to decide whether the feature fits the app and what the overlay should show, since the thread has been idle for about 292 days. Done would mean an agreed specification, not a patch.

Checklist

• I made sure that there are no existing issues - open or closed - to which I could contribute my information.
• I made sure that there are no existing discussions - open or closed - to which I could contribute my information.
• I have read the FAQs inside the app (Menu -> About -> FAQs) and my problem isn't listed.
• I have taken the time to fill in all the required details. I understand that the request will be dismissed otherwise.
• This issue contains only one feature request.
• I have read and understood the contribution guidelines.

Feature description

Solution
On the gazing position (~middle keyboard) an overlay can be shown, which shows the current word.

• The last letter of the word always stands in the same place (new key types push the "old" letters to the left, so the word grows to the left).
• When the space-key is pressed and it wasn't autocorrected, it still shows the same word (maybe only for at most 3 seconds unitl the overlay hides). If a key for a new key is pressed and a new word begins, the overlay shows the first word letter (begins anew).
• When the space-key is pressed and it was autocorrected, the overlay shows the autocorrected word on them same position (and maybe the phone vibrates in low volume). The written word is shown above crossed out.
  • (If the auto-correction was right relevant) Same behavior as above with 3 seconds (or so) until the overlay hides, or alternativly a new word was begon.
  • If the auto-correction was wrong. Click/swype for showing all possible other corrections including the original writing. Or delete the last single letters or delete the whole word.

I think it's best to see what I mean in an animated GIF, so I made one (which took longer to make than i exspected, but hopefully it has some value), click to make it bigger:

(The overlay is transparent)

The last written letter could be emphasized in some way, but such things are details.

Small adjustment: It would be good if there would be a visual emphasis on the current letter, (which is the watch anchor / gaze anchor / focal point) and typing is using peripheral vision. E.g. by a highlighting with an additional background rectangle.

E.g. like this:

(the rectangle isn't perfect matching the letter and it's color could be better, but you see, what i mean)

Why do you want this feature?

Feature idea

Related optimization problem and use case
This Feature Request aims to optimize writing speed of correct written words. It's adressing fast typers.

Fast typing is hereby defined by >= ~200 keys per minute (you can test e.g. here). It can be achived by e.g. using both thumbs (which here may be assumed).

Key observations for the problem
1. The optimal gazing point while typing is imo in the ~middle of the keyboard.
This way the periphal gaze can catch all the keys on the keyboard best. This increases the typing precision.

You see the gaze is a bit higher than middle, this may be good because the thumbs might be blocking the view on the lower position for the overlay (but that I'm currently not sure about, because the thumbs are normally moving).

2. The high feedback loop with suggested word forecasting (while typing) probably isn't useful for most fast typers.
Fast typers are so fast that the cost of viewing the possible suggestion-completions (and recognizing them) is higher than just typing the word to end fast.

3. Still: A low-cognitive-profile feedback of what is typed, is still useful for improving accuracy of key-typing
Seeing which letters are currently hit is probably still interesting for improving key-typing accuracy. It has a low-cognitive-profile because that is currently, what was mentally adressed anyway and should typically be exspected result (except when a wrong key was hit). Also it can be showed where the gaze already is in place.

4. Still: To see a word was written wrongly (and also correct it) is still useful, especially if the word was completley written.
This can be done by showing the current/last word on the gazing place. Also, if auto-correction is on (probably recommendable), the words should came out as wanted (because it was manually typed) in most cases if it wasn't corrected. And if it was corrected by the auto-correction it can be shown in place and also make the phone vibrate. This should appear when the spacebar was hit, showing the current wordwriting is finished .

Additional information

No response