[MPTCP] insonsistend subflow creation policy ?!?

Hello, I just noted that the pm_netlink subflow creation policy is inconsistent (or perhaps simply different ?!?) between signal and add_addr subflows. When the MPTCP socket tries to create additional subflow due an 'subflow' endpoint, it will filter out local addresses already in use by existing subflow. When MPTCP tries to create an additional subflow due to an incoming 'ADD_ADDR' option, it will try to create it regardless any existing subflow using the relevant remote address (and port). Should we change the above ?!? (e.g. applying some filters even for ADD_ADDR). Or perhpas add some additional policy flag (like 'unique' or 'none') ? WDYT? Thanks! Paolo