1. A method in a data storage system including a non-volatile memory array controlled by a controller, the method comprising: in response to receipt of write data to be written to the non-volatile memory array, the controller determining whether a read count of an unfinalized candidate block of storage within the non-volatile memory array satisfies a read count threshold applicable to the unfinalized candidate block; and in response to determining that the read count of the unfinalized candidate block satisfies the read count threshold, the controller finalizing programming of the unfinalized candidate block and programming an alternative block with the write data, wherein programming the alternative block includes programming a physical page in the alternative block with a data page forming part of a page stripe spanning multiple blocks.