I believe we are mostly on the same page. Voting should be in person, on paper, on a weekend day. It can be done, even in covid times.
One more thought: Simple >>> Complex.
Small variations in a technically correct process may break some of its properties. The more complex the process, the easier is to inject variations, some of them adversarial. If gerrymandering is to be taken as an example, this can be taken to quite some extremes by two sides driven to win the zero-sum game at all costs. But even in absence of that, bugs happen.
To nitpick one detail, I'm not persuaded by the secrecy violation prevention argument. You either prevent secrecy violation by anonymization, or you prevent vote fraud by keeping a link between the voter and the ballot. You can't have both at the same time. In person voting minimizes the bounding box of anonymization: in space, at the ballot box, and in time, the election day. Hopefully both parties afford to have observers during this space-time interval. As you spread out the voting process, both spatially and temporally, it becomes increasingly impractical / too expensive to maintain observers of the entire process.
