Thanks…
This is why…
The OpenWrt driver to unpack the Mikrotik board data (https://github.com/openwrt/openwrt/blob/e722b667c5a59bbd5aff787002f7f5457d0bf721/target/linux/generic/files/drivers/platform/mikrotik/rb_hardconfig.c#L566) does not have the functionality to deal with this LZ77 data.
I think I previously worked out the block format for it, but I didn't have a need to build this into the driver: https://github.com/john-tho/routeros-wlan-lz77-decode.
It would help if you shared an image dump of your hard_config partition (does contain device-specific serial & MAC, but I would not share them, can PM me if wanting to keep private). That way we could test to see if my block format guess would still work for your LZ77 data. If so, someone would need to add this functionality to the driver, or (for now), you could extract the data, and add it to a board-2.bin file like was done before the Mikrotik per-device BDF PR: https://github.com/openwrt/openwrt/pull/4679
. /lib/functions.sh
dd if="/dev/mtd$(find_mtd_index hard_config)" of=/tmp/digga_hapac3_hard_config.bin iflag=fullblock