DMGConverter

This utility is more than its name implies. Besides helping you convert DMG files to various formats, you can also use it to create other types of disk image files, encrypt ISO files, split NDIF or UDIF disk images into multiple segments, and so much more.

DMGConverter supports drag-and-drop actions, features easy-to-configure output settings, and supports multiple disk image formats. All you need to do is to select the type of task you wish to complete (choose one of the panels listed on the tool's interface), configure the output settings according to your needs, and drag-and-drop the file or folder for processing. You can't access other built-in tools or configure the tool's settings while it's generating the disk image file.

My only issue with this tool is that it might take a while to generate the DMG files you need. In my testing, DMGConverter spent several minutes to create a DMG file from a 500MB folder. It also crashed one time, when generating a disk image file. Still, the reason for the crash isn't clear, it could be my Mac's fault.

All in all, I think you should test this utility on your Mac and then decide if it's worth keeping it. You have nothing to lose as DMGConverter comes without a price.