It could be engineered in a way that allowed that.
Vouching is undoubtedly a complex process. It is resisted in many jurisdictions because it delays your official voting result. It has been a feature in British Columbia for many decades. It is the way in which the provinces enacted the ability for any registered voter or any eligible voter in British Columbia to vote at any voting location, and this is right from the days the writs are issued until election day. If voters for some reason cannot get to their assigned voting place, they can vote at any other voting place in the province, but because they're not on the list for whatever place they're attending at, their ballots go into what's called a tendered ballot envelope, and those all get shipped back and forth across the province in the 10 days that follow the election, and then on that 10th day they're all reviewed and scrutinized and counted. If a person has voted before, that person's vote is not allowed. If a person is not registered and claims to be, that vote is not allowed.
It allows that scrutiny, which may be something that could be engineered for the vouching process.