surrogateescape not working

[muelli]

I'm seeing this behaviour in Python 3:

Python 3.5.2 (default, Nov 17 2016, 17:05:23) 
...
In [1]: s = b"fo\xf6\x65\xe9\x62a"

In [2]: s.decode('utf-8', 'surrogateescape')
Out[2]: 'fo\udcf6e\udce9ba'

In [3]: s.decode('utf-8', 'surrogateescape').encode('utf-8', 'surrogateescape') == s
Out[3]: True

And I expected Python 2 to behave the same, after I use python-future's surrogateescape. This, however, is not the case:

Python 2.7.12 (default, Nov 19 2016, 06:48:10) 
...
In [1]: from future.utils.surrogateescape import register_surrogateescape

In [2]: register_surrogateescape()

In [3]: s = b"fo\xf6\x65\xe9\x62a"

In [4]: s.decode('utf-8', 'surrogateescape').encode('utf-8', 'surrogateescape') 
   ...: == s
Out[4]: False

In [5]: s.decode('utf-8', 'surrogateescape').encode('utf-8', 'surrogateescape')
Out[5]: 'fo\xed\xb3\xb6e\xed\xb3\xa9ba'

I expected the values to be the same.