K5 Paperwhite: left alignment per default?

Hi all

Yes I kow, this question already exists. But I found no proper answer.

Problem:
I want to aktivate LEFT JUSTIFICATION as default.


I was able to activate the left handed justification of text in MOBI-books and Kindle-books over altering the CSS-file in epubs and converting the book into mentioned fitle types over Calibre.
But this is a cumbersome solution.

I indent to make LEFT JUSTIFICATION default.

Questions:
Is there a hack (could not find one) for doing this job?
Is there another way (e.g. altering one specific file somewhere hiding on the Kindle PW) managing this?

And a rhetorical question:
Why on earth does one of the best ebook readers on market as a single purpose machine not having this option to at least let typo fanatics chose?

A.