Under the covers the New-VM cmdlet uses the CloneVM_Task method.
But afaik there is no way to tell this method to use a non-quiesced snapshot.
What you could do, is to create a non-quiesced snapshot yourself, and then create the clone from that snapshot.
But that will require you to use the CloneVM_Task method instead of the New-VM cmdlet.
Out of curiosity, why would you want to clone from a non-quiesced snapshot ?
