problems related to the use of bioethanol are: corrosive effect on fuel injector and electric fuel pump (bioethanol is hygroscopic in nature), engine startup problem in cold weather conditions (pure ethanol is hard to vaporize) and the tribological effect on lubricant properties and engine performance. Bioethanol inside lubricant significantly reduces the properties and performance of engine oil. It is miscible with water, but immiscible with oil. Therefore, bioethanol has high potential for emulsion formation (bioethanol-water-oil mixture), which causes serious engine failures. There are different methods to improve the performance of engines (e.g. laser texturing, coatings, mass reduction of engine parts and lubricant composition) and extend their lifetime through the friction and wear reduction. The use of synthetic oil is one possibility to solve the above-mentioned issues (16).
Doesn't sound to me like there is "nothing to worry about" using this stuff in engines not designed from the outset to use it.