I don’t know from experience of any clogs, but I would think at just 43k you should be fine.
Mileage is always affected across the board. Of about 3 years of logging (12000 miles), E85 has averaged about 15, mixes around 17, and 18 on premium.
In terms of cost, mixes have saved me 28% at only 8% mpg loss compared to premium, which I record cost of every time for comparison.
e85 saved 31% but 20% mpg loss.
I should note all e85 tests were during summer months, and winter months is mostly premium only.