I've never seen a reason why mining rewards should stay on the pools longer than necessary, so I've always set it to the minimum payout amount.
I have of course changed this now.
But I had never heard of it before, which could cause problems at some point.
Normally it's not much of an issue in most wallets, unless we're taking about thousands of small payouts.
That setting will also save you some satoshi later when you need to spend your mining rewards.
Because could cause you to pay more fee if you end up creating transactions with high number of inputs (
higher transaction size).