If I have a BT mobile 12 month SIM, which I understand gets me free access to BT wifi spots, do I still have to opt-in and give up some of my homehub or can I leave the homehub "private" and have the mobile automatically log in to the BT hotspots?
Furthermore what's th benefit of the bt wifi app? I thought most smartphones would login when you've done it once anyway- negating the need foe the app- or am I missing something?
Its a benefit of having the sim so you do not need to have your hub sharing in a mutually beneficial way. However, shutting off the sharing on your hub does not increase the performance of your connection, your broadband gets priority and the public bit gets unused bandwidth.
Additionally, people who use the public access part have no access to your network, nor are you liable if they do anything illegal with the connection.
I did tests with and without the public hotspot active on speed test and with pings to gaming servers and there was no difference.