It simply has never been requested by any user since the release of TMP back in 2014. I suspect this never came up again because it breaks text layout conventions.
Like I said before, I am not opposed to looking into adding this type of functionality. This would likely be a new Overflow mode called Character Wrapping.
P.S. Another user requested the opposite which is when Word Wrapping is no longer possible as a result of the width of the text container being too narrow, to never break up words and to have those words overflow. This would also be a new Overflow mode which I am not sure what to call yet. Overflow Mode = WordOverflow?