I have a 2018 X-Town 300 i. If I'm not mistaken, it says that it requires Hi Test gas.
With 2500 miles on the bike, I performed a little experiment. I ran a full tank of gas with high test and a full tank on regular. There was no pinging, or engine detonation, on the regular gas, usually the first sign of too low an octane fuel, but the really telling thing was, I got 65 MPG on regular gas, while only getting 59 MPG with the Hi Test. That is usually an indication of the engine is running at it's optimal performance.
I was very careful and accurate with both tests, making sure the volume of fuel was identical and the travels and usage were the same.
This would indicate to me, that it's perfectly safe, and even beneficial to use regular gas. Any opinions?