IDK what version of Veracrypt you tested but I still have a working version 1.24-6 released 3/10/2020 , more than 2 years before you wrote this, and it accepts extended ascii, although AFAIK not when encrypting a system drive due to pre-boot environment limitations. That said you don't need extended ascii for secure passwords. Using nothing but the letters, numbers and shift variations on the numerals on the standard US keyboard gives you 72 characters. With a 15 digits random password and 1 billion...