One thing I just happened to come across randomly, but after testing it a few times, I've determine it does seem to be happening. ImgBurn can eject a disc with the Eject command even when a "write operation" to a formatted disc as a giant floppy in File Explorer has not completed yet.
I don't know if there's a way to check for this before ejecting, but if there is, can it be added to ImgBurn? The way I do it now, to be safe, I don't use ImgBurn's Eject command when a disc formatted as a giant floppy by File Explorer is in a drive. I use File Explorer's Context Menu Eject command. If the write operation hasn't been completed yet, File Explorer won't eject the disc.