I've read the admin guide, and make some tests, but I don't see the difference between:
Enable Split Tunneling with allowed access to local subnet
Enable Split Tunneling
Both keep the default route and local routes....
When the "allowed access to local subnet" is selected the local subnet will always win in routing decisions. This is defined as the network and mask assigned to the local computer nic.
Normally in split tunnel the network list downloaded to the computer will override any local routing table options and send traffic up through the tunnel. If there is an overlap in this tunnelled traffic list with the local subnet you will lose access to local resources like printers and file shares.