Interesting idea. I think the particles could look cool in a night flight. Moreover, a similar effect in the real world can be created by flocks of large insects or snowflakes.
As for the fuel shortage. Which island did you try to land on? If you turn around immediately after the finish line in the opposite direction, it does not matter whether the turn is made in a vertical plane, in a horizontal plane or in a spiral, the fuel supply will be enough to land on the departure island.
There is enough fuel even if you keep the engine power at 100% all the time during the race (from start to finish). Landing on the island without reducing the power below 100% is, of course, not possible. But for landing, a small power is enough. Landing is possible even with the engine turned off. If you move in the direction of the finish line economically, that is, at a low speed, it is possible to overcome the gate and land with a fuel reserve of 50%. Of course, in this case, you will come to the finish line last.
The amount of fuel is also sufficient for landing on 2 other islands after the finish. I deliberately limited the fuel supply enough to make landing a challenge. Perhaps a scoring system will be added to the game, including for achievements in fuel economy.
Thank you very much for the detailed comment!!!