I can only judge a trick by how I use it. Typically I perform for friends, family and social
situations. The people know me and ask me to do tricks over again. Kids grab the items, etc etc etc.
Not the forum for tricks that have to be done in the perfect angle. And this trick does not
allow for any bad angles.
DON'T LOSE THE BALL!!!
Angles are not an issue, your audience just needs to be in front of you. Your fingers provide more cover if you need it.
Once the change is done and the ball is bounced you are clean. I perform for handsy kids too, the solution to this with this effect is to change it into a ball and bounce it to them. They catch it and it's completely examinable. The hard part is getting the ball back.
To change it back, grab a regular quarter and do a simple spellbound move. In a casual situation, you have ample opportunity to do this.
It's a general rule in magic to not repeat yourself, but in this case I have repeated this trick for the same audience of grabby kids without an issue. The trick is to control your performance conditions. Don't just do it twice back to back. Perform it once, let it marinate. Change it back into a quarter. Let it marinate. Then hours later when you are ready, do it again.
It's a quick trick, and it's not meant to be scrutinized but the switch is so natural it will easily pass two or three times for the same audience, especially if you occupy their hands by bouncing the ball toward them.