Isn't the proposed workaround also relying on CPython reference counting to immediately deallocate the sliced view? It fails if I keep a reference to the sliced view:

    byteslike = bytearray(b'abc')

    with memoryview(byteslike) as m1:
        m2 = m1[1:]
        bs = bytes(m2)
     
    >>> byteslike += b'd'
    Traceback (most recent call last):
      File "<stdin>", line 1, in <module>
    BufferError: Existing exports of data: object cannot be re-sized

It seems to me that it should be written as follows:

    with memoryview(byteslike) as m1:
        with m1[1:] as m2:
            bs = bytes(m2)

    >>> byteslike += b'd'
    >>> byteslike
    bytearray(b'abcd')

The memoryview constructor could take start, stop, and step keyword-only arguments to avoid having to immediately slice a new view.