I know that for written books, this isn't an issue, json text functions perfectly.

But for writable books, the pages:[] tag refuses to process anything but a pure string, disallowing even newline characters.

I know that the book is capable of holding this information, but Minecraft doesn't seem to allow users to input the info. 

I have tried copy-paste, tried most every method of reformatting the command, I've tried it with the book in a chest, lectern, item frame, item, in my own hand, but it doesn't seem to work.

The parameter used was pages:['\{"text":"-\\n-\\n-"}']
Which resulted in the text)    {"text":"-\n-\n-"}

Could the mismatch be in how written books can hold unadulterated user content, and therefore not have gone under some sort of verification/solidification and so is treated differently?

As far as I can tell, this has been here since a minimum of 1.13

Thank you, Goodbye