It would be nice to have an option on the conversion dialog to "save a backup copy". When converting from format to same format, say maybe with the new heuristic settings, things sometimes get worse and you've overwritten your source.
I haven't figured out what the best mechanism to "undo" a botched conversion would be though
I currently open the folder, copy/paste the file, then try the heuristic options, renaming/retrying as appropriate. Seems like there's an opportunity for a smoother process.
Maybe subsequent conversions could offer a "backup" to "format", and then you simply remove the backup file from the book later (or keep it if you choose).