I dunno if this ours, or an upstream enhancement, but I was just rebuilding a 6.5 box with 7. I selected custom formatting.
1. It seems to autoselect *ALL* drives. I would strongly argue that it should *only* select the first drive, or whichever is already bootable. That could be disastrous if someone doesn’t notice they’re all selected.
2. There’s NO BACK BUTTON once you get into the select mount points, etc, screen. The only way back seems to be a reboot.