I wouldn't do it because I do think it is shady, but I can understand the appeal of it. FP+ has made it so we get fewer fast passes than we did back when old FP was still in use. We are also standing in longer lines for rides that we never did FP in the past. We are unable to ride certain rides multiple times with minimal waits like we once did. And, we are spending more money to experience fewer passes, longer lines, and fewer rides. I get why people would be tempted to use multiple magic bands to get multiple passes. I don't think that they should, but I get the appeal.