i'm a bit new on the ground. trying to explore how does it work in theory?
when miner selects transactions for candidate block, they usually pick transactions with higher fee. can they pick any valid transactions with significantly low fee? if they can, how all these things work? is it manually adding a list of transactions? or automatically? i guess if it's an automated process, miner can't pick low fee transaction at all but i read that miners can include any transactions they want for the candidate block.