I saw "Multiple consecutive newlines in books do not create a space between lines in editor" was fixed, however, I am curious if this fix corrects the Spacebar issue as well as the NEWLINE one.

Just like with the NEWLINE issue, If the cursor in the Book and Quill you are editing is on the far left, hitting spacebar will not move the cursor, however a SPACE will be made in the typing memory just not be visible.

For example, if you do the following

Open a new quill/book
Type A,
HIT ENTER to go to next line
HIT SPACE 10 times (no space will actually be made when you do this...)
Then Type B. this will give you the image I have attached. The B will be on the first spot on that line directly below A. However, if you now hit backspace, it will take 13 hits of backspace to delete everything. Because the invisible Spaces require being backspaced before you can delete the A.

This issue also prevents you from centering text without first putting something in first spot on that line.