If you're not comfortable with the lack of real board real estate and lack of direct manipulation of the board, try these! You may need the wedges to make 'em longer, but trust me, you'll feel the difference in confidence and stability.
The extenders are a great add on to the minis if you want your feet slightly away from the tire. You feel more locked in having your foot placement a little more centered on your footpads while still having contact with the fins.
Great setup and they really helped me out.
I have the Flight Mini for Ambidextrous reasons, these extenders game me the extra support. Now I have the lock in feel of regular flight fins, but I have the ability to switch easily. Or have friends that right different from me ride my board. Which is great because I ride Goofy style, so friends can hop on and get the lock in feel too. Would buy another set for my future Onewheel, except that will be a full flight fin combo