It sounds like that process involves at least one signature that would have to be forged, and a backend process at least manual enough to result in some physical mail arriving at the voter’s address afterward. Then, when the voter arrives at the polling place, they can still cast a provisional ballot [0]. Which will count when it’s reviewed, and which, if it happens at scale, seems like it would flag up the scam to the canvassing board.

If you’re willing to make fraudulent representations to the elections office, it seems like a wide variety of online services might be at your fingertips, like concocting new voters with a similar amount of information [1].

But in both cases, it seems like the main security measure is “the feds are very eager to help the locals investigate when elections are tampered with, and judges really like throwing people in jail for a long time for willfully lying in connection to elections.” E.g. [2]

[0] https://sos.ga.gov/how-to-guide/how-guide-voting#Provisional...

[1] https://mvp.sos.ga.gov/s/voter-registration?IsRegisterNow=tr...

[2] https://www.cnn.com/2021/05/03/politics/pennsylvania-probati...