Half Moon can be a tricky pose- especially without a prop! Most people think to use a block here but the wheel will give you more space between your hand and the mat. The rolling wheel also makes for an easy adjustment!
Just like Half Moon, Sugar Cane is much easier with a prop.
The wheel is an awesome tool to get your plank off of the ground by placing the tops of the feet on the wheel and walking the hands forward.
Turn this into even more of a core workout by bringing the knees to the chest and the pelvis into the air for a variation on Bakasana aka Crow. The wheel will help to build muscle memory and get the body up into the air.
The wheel is one of the best tools you can use when trying to get upside down! Once you feel comfortable enough to move your inversion practice away from the wall, the wheel is the next step to allow you to build strength and muscle memory while providing a small assist with balance.
I hope this has inspired you in your practice!