I just quickly searched up an article and you seem correct.
https://abcnews.go.com/Business/wireStory/epa-raises-amount-ethanol-blended-gas-85186380Generally, the label at the pump says up to 10% ethanol. Probably not in California but in some areas, there is recreational no ethanol gasoline in the 90 ([r+m]/2) range. The article speaks in terms of total ethanol used a year not in what min or max at the pump labeled up to 10%. Generally, chainsaws weed wackers and that sort of stuff say 10% max ethanol. The twin turbo Ford ecoboost engines pretty sure are 10% max, probably hasn't changed lately. There is E85 so perhaps the extra ethanol could go that direction. I get the AMA magazine and they sure don't like the possibility of 15% ethanol pumps showing up.
As far as the ethanol discussion it is kind of political.
there is some byproduct essentially protien that is used in livestock feed that in all fairness should not be totally neglected in the discussion.
There are breedings or modified variants for use in the ethanol is my impression sort of like the corn for popcorn is different.
Sure, land prices got elevated hard to discount this in the ethanol evaluation
The fertilizer aspect, a it comes generally from natural gas, b when it runs off and gets into the gulf of Mexico it makes a dead zone.
Till type farming is kind of hard on the ground long term. Not sure where we are now a days with paying to give acreage a rest from the federal government.
Best I understand it the only things approved to add to the gasoline were mtbe and ethanol. It does reduce some tailpipe emissions, who knows if you back off and look more broadly. mtbe has or had groundwater issues from spillage is my understanding.
The same thing could be analized for turning soybeans into up to 20% of diesel.
It is a comment not sure it is an answer to your question.
Fran