I'm in the same situation as you (missed the kicksterter, bought in late).
I was able to find the .6 version in my Itch Library ( https://itch.io/my-collections Click the 'download' under Beamsaber). In my case it was the last entry on the page - on account of it being alphabetically inferior to the rest of the entries.
Spoiler: The phrase "Header art is space battle" no longer appears in this book.