I read somewhere that the slot leader is determined locally by the block producer node. Is that true and if so, would that mean that there is a lottery on each BP node with a potentially conflicting outcome? When there are multiple BPs proposing a block for the same slot, how is it decided which one to take?
I was also wondering, whether it is known upfront when a BP is expected to do some work? If not every slot is equal, there would be good/bad times to do maintenance (i.e. take the node down for a little while).
In other words, for how long can a block producer go offline without forfeiting its chance to mint a block?