As an extension to this functionality, it would be great if holding down the Shift key whilst dragging the spacebar selected the text! (i.e., when you hold down shift, the spacebar effectively becomes the same as a trackpad).

Re: the vertical cursor movement limitation:
A workaround suggestion: It might be possible to work around that by coding it so that:
- if upwards/downwards movement is detected, the cursor moves back/forwards approximately the number of characters in a line, say 40 or so characters. It doesn't really matter if it doesn't end up exactly above where it was, all we need is to go backwards in our document quickly!

- I know there's not much space for downward movement, but there's a few mm, and perhaps if we slide down a few mm and hold, the cursor could keep moving to the right by approx 40 or so characters per each 0.2 second (or so) until you release your finger.

Yes, I would say that Apple iOS keyboard's hold/slide function on the spacebar is _extremely_ useful (but not essential) for moving the cursor with precision, especially when you need to move a long way (further than using the arrow keys). It would be of _great benefit_. It is difficult to move the cursor a long distance by sliding on the text, as one often inadvertently selects the text.

It seems to me that having auto-repeat on the spacebar is beneficial to a small degree occasionally, but most users would not regret losing it, as repeatedly tapping the spacebar is not difficult. It seems to me that it is only rarely that most people would need multiple spaces.

The standard Apple iOS keyboard seems to have no problem with accidental triggering of the cursor move function (I have never triggered by accident). Even if some users trigger it accidentally, it's not a big problem. If you can come up with the same behaviour as the Apple iOS keyboard, that would be good. If you think it gets triggered accidentally too often, you could increase the delay before activation.

Summary:
Hold/slide spacebar to move Cursor:
- Great benefit (for distance and precision)
- Distance and precision cursor movement function difficult to achieve in any other way
- On standard iOS keyboard, it is difficult to trigger accidentally, and it's not a big problem if it does.

Auto-repeat on spacebar:
- Limited benefit, only occasional usage for most users
- easily replicated by repeatedly tapping spacebar

Yep it would be great for people rewriting alot 😉 I've tested this on another keyboard app, it so powerful and you're getting used to it very easily.
And it wouldn't change the "Apple" layout you want to stick to.👍