Firstly the crew have all my sympathy, there but for the grace of God!
Given there are "line up allowances" depending on geometry of taxiways, whether it's a runway where you have to backtrack and do a 180 at the end etc., (yes I realise this is not the case for RW 16 at DUB) how necessary is it to squeeze out every bit of tarmac on the line up against the risk of leaving the paved surface?