I have a resonably healthy lawn apart from many bumps due probably to over enthusiastic hurlers using it in damp conditions. Would you recommend rolling it? I realise that a very heavy roller would probable do more harm than good but maybe a half filled water roller would do the job?
Minor bumps tend to level themsleves out over a period of time due to action of weather and earthworms. You can roll a lawn to level small surface unevenness and it is best down after rain but not when the ground is so wet that it is squelchy as this can cause damage, and do it only once or twice.