Inside the Curl asked me in another thread in 2019 was it mandatory to sign up in person for all the contests. Here was my answer copied from that original thread. It may shine some light on the subject..........
"Well, yes and no. There are a few proxies that, for a small fee- will have someone sign up on your behalf and save you the initial trip to Vegas. You should sign an agreement form with the proxy/signer upper, clearly stating the business arrangement- which both parties must sign. They should have a copy of a decent blank agreement form. If you happen to win some cash, they can fill out an IRS Form 5754 which relieves them of having to pay the taxes and transfers it to your responsibility, along with the $$$$$$. I know of 1 or 2 proxies that can sign you up, but not sure they would want me to post it here. Message me and I can point you along. They may be booked up though, I wouldn't wait too long if you're interested in going this route.
BUT KNOW THAT, under the rules of every contest in Vegas- you must show up and sign up in person. Most also force you to sign up with their "Players Card" or whatever their particular members card is so they can track your poker and slots playing, etc. That's free though, no big deal. So, the arrangement would be handled inconspicuously, and you won't be the one getting your picture taken if you place #1. LOL
I wanted to add I did this a few years ago, it went fine with no hiccups. You just have to trust the people you're dealing with, as you are forking over the entry fee and proxy service fee to the service before hand. But you can direct them to use whatever name or "handle" you wish. Some services will email you a copy of the your submitted entry form each week, others just send an email confirmation. And others may just text you. I'll be under "sshz" for my contests this year, so you can follow along for the ride. All the contests have websites with the weekly standings (and I think picks for all the entries)."