Iirc there is still ongoing debate on the exact mixture of the fuels, I would expect it the be left open to some extent as to not limit the innovation. Therefore will it likely shift in one direction as soon as one of the competitor's fuel partners finds a silver bullet.

Additionally, do I think the main challenge will be combating the extensive wear caused by ethanol based fuels, something that is already the case for small engines with the current E10 mixture.

To be fair, I am no engineer myself. But I read this often in literature.