There is PR raised for it already, just waiting for the final approval.
the live_time is just used to lower the quote bit, to encourage nodes staying longer with the network.
it’s not a direct reward, just a factor to make network being more stable in general.
Because new node need to store replicated copies as well.
And node owners intends to see the node is working via earning.
So this factor just to allow new node have a better chance to be picked,
so that the owner won’t feel bored and unfair, before restart the node.