No. (and there is nothing specific to my build)
Maybe the earlier discussion about that gives you enough answers:
Forum search:
https://forum.openwrt.org/search?q=print_req_error%3A%20I%2FO%20error%2C%20dev%20mtdblock1
Leads to e.g.:
Are I/O errors on mtdblock concerning? - #4 by joaoabs
and
Blk_update_request: I/O errors - #27 by Doppel-D
Leading further via https://openwrt.org/docs/techref/flash to https://bugs.openwrt.org/index.php?do=details&task_id=1871 that contains the detailed explanation:
Reason for closing: Not a bug
Additional comments about closing:The first few blocks of a NAND flash are guaranteed good to ensure that a bootloader stored there can never get corrupted, so it will get written without valid ECC data (the SoC won't check the ECC anyway).
When block-mount scans all block devices, it will try to read from those blocks, which are exposed as partitions, and the NAND driver will report failed ECC checks (the I/O errors in the log).
There is nothing wrong here in either way, and nothing we can really do to prevent it.