I wrote an app to do that myself but it currently only does Windows ISO images and anything based upon WinPE or WinRE such as the Macrium Reflect recovery media, etc.
Let me tell you a few of the features so that you can tell me if you think I should try to add Linux support to this. It's been something I have been contemplating but I don't use Linux at all so I never had any motivation to add that capability.
1) The resulting media is bootable on its own so that you can use it on a system with no OS or if the system cannot boot without needing to configure anything on another computer.
2) Once booted, you select from the available ISO images and it will reconfigure the media to boot that ISO image. It can be configured without having to boot from it as well.
3) It can create multiple additional partitions so that you can use the same media to store other data as well. It can even BitLocker encrypt other partitions while the media is being configured.
4) It can update the bootable portion of the media without loosing any of the data on the media. It boots using WinPE but if a new version of WinPE comes out it can be updated nondestructively.
5) When done, just run a single command and it restores the media back to its original state, all ready for you to select another ISO image to make bootable.
In my case, I keep about 10 Windows ISO images on it, Macrium Reflect recovery media, Veritas System Recovery, LSoft Active@ Disk Image, and a few other utilities.