That sounds like a lot of struggle over something the predictive text bar already does ?
In my experience when you delete a word, or a whole sentence, it'll be the only suggestions from the predictive bar at the top of the keyboard. Tap that suggestion and you get your stuff back.
I've used Florisboard on my device for a few years now, and completely shocked at how barebones the stock Android and Samsung keyboards are...
It can undo, redo, cut, paste, select all, view/insert clipboard history, clear clipboard, and swipe to move the cursor within text. Standard stuff like voice input and swipe typing are here too.
Admittedly it's not perfect, and probably not ideal for most casual users in its current state, but I just can't go back to a standard keyboard after using this feature rich one for so long
I tried so hard to stick to Florisboard but gboard is waaay too convenient that I keep going back to it.
I wish Florisboard at least adds feature to search among emojis.
So... even after setting it up, I have to switch keyboards before I can undo, then switch back (or continue typing in Japanese)? I'll just retype while waiting for the official solution...
EDIT: Just today, I noticed that when I mass-delete by swiping left on the keyboard it deletes (obviously), but moves the text to the auto complete bar!? This is a single tap to restore which is way faster than the method in the article. Is this Google's implementation or a Pixel-exclusive preview feature?
Gboard is frustrating because it's the best keyboard I've found, but it also has so much obvious room for improvement, but Google had hardly worked on it at all for years. For example, the way it handles ellipses and hyphens makes you fight the keyboard if you want to follow the rules of written English.
Okay, that's good to know. And I agree. I think many of Google's apps these days are pretty much fine, but they don't put the effort in to fix obvious things to get them over the line to "great"!