Okay this happend to me, both with palm reading and the cube; with different girls.
So I started doing the cube to this girl (isolated) and suddenly she get so excited she just hold my hand and tell her friends I was the best guy , bla bla , and everyone wanted me to run the cube , so I said it wasn't the best time , I isolated once more the target and told her that was rude , cuz it was a secret btw me and her

she laugh and we continue talking . With palm reading was almost the same story.
In the other hand girls love when I do any cold reading thing ( Palm reading , cube , etc... )
I will tell you from my experience two things:
1. You have to options to use the cube /palm at A2 as a hook , to keep the girl into you and then move to A3 or you can use it in C1 and will work perfect. This kind of routines are really ood to help you Isolate any target , but try to keep it low , or all the group will want you to make it for each one.
2. About your question of using the cube with the whole group , this will be a great DHV you can use it in A2. Let me show you a quick example:
XF: LEts play a game.... Everybody close your eyes and think of a Cube... now tell me in secret how big /small is your cube (let each one tell you he answers in secret. *Note: You can Neg your target here , by asking everybody answer's but don't ask her... she will want you to hear her answer , tease her a little bit.)
Then explain each one the meaning and tease your target by saying something like:
XF: Okay now , You (Target) -You told me your cube was really huge , liek the Sears tower , We can see that you have the biggest EGO ever... I don0t know how you guys hang out with Miss Huge EGO

...
Then call and tell her that you want to tell ehr a secret or any thing , and isolate her.
A quick adaptation of the cube , to perform in a group.
*NOte : The cube used in C1 will make a strong connection and will build rapptor really fast between you and her. SO is your choice , when to use the cube and with one person or in a group , hope this help you Zenit.
i like your information, but my god, you should proof read your post before you submit them.