I'm guessing what could be considered low-hanging fruit would be that the original 4&4 encoding was later surpassed by much more efficient 6&2 encoding a few ye

I'm guessing what could be considered low-hanging fruit would be that the original 4&4 encoding was later surpassed by much more efficient 6&2 encoding a few years later. And even then, the 6&2 encoding scheme chosen wasn't ideal as it took too long to decode. Later intrepid programmers were able to decode an alternate scheme of 6&2 in time to read an entire track within the revolution of the disk and get closer to ideal performance and data density.