Why Base64? QR codes can contain pure binary data, no need to use this inefficient, not-error-correcting 6-to-8 encoding.
Oh, I forgot Microsoft does not care jack shit about saving people’s computing resources. However, Windows 9x installers on floppies used custom formatting except the first bootable one, allowing them to fit nearly 2 MB of useful data per floppy.
They can contain binary data, but less of it. Not sure of the details, but you get 3k bytes if binary data or 4.2k alphanumeric letters. So no big difference all in all, which is a bit silly.
Also, many QR scanners can’t handle binary data and freak out on null values or newlines.
We must consider the practical side of installing Windows 11 from a semitrailer load of cardboard.
The alphanumeric mode does not support lowercase though, it has 5.5 bits/char (pairs of characters are encoded as a base-44 numbers in 11 bits).
