The rewards are not noncustodial, the pool still tracks them and decides when and how much to pay. The only difference is the pool pays out faster/more often than many other pools. However, pools doing lightning payouts are even faster!
Discussion
Also, it’s important to note that many miners can only handle coinbase transactions of a certain size, so there’s a very low limit on the amount they can pay out in coinbase transactions, much higher than dust.
