I confirm: Python 3.10 works as expected.

Python 3.10 fails with the same SyntaxError using "python script.py" or "python -m script" if the script contains non-ASCII characters but is not encoded to UTF-8.

vstinner@apu$ python3 test.py
  File "/home/vstinner/test.py", line 1
    print('�Hello world!')
                         ^
SyntaxError: (unicode error) 'utf-8' codec can't decode byte 0xa1 in position 0: invalid start byte

vstinner@apu$ python3 -m test
Traceback (most recent call last):
  (...)
  File "/home/vstinner/test.py", line 1
    print('�Hello world!')
                         ^
SyntaxError: (unicode error) 'utf-8' codec can't decode byte 0xa1 in position 0: invalid start byte