Theres all sorts of issues with both. Lets start with the flange. First and foremost it will allow water to get behind both pieces of metal and will rust, two, it looks like *** from the back side, three, its a hack method. Five, no one welds a continuous bead on sheet metal. If you do you might as well throw the panel out in the street and let a forklift run over it, it will be so warped.
The plug welds then bondo is just NONONO. Asking for rust and the bondo to crack. Those two types of repairs are the kind that gypsies do on rebuilders. Crap like that gives guys like me a bad name.