> Multiple installs on the same device are not supported.
If one is limited to a single usb-stick per ISO, it's just easier to dd the installation image: run it the way it's (hopefully[x]) been tested by the vendors.
Ventoy is a different ballgame: drag & drop ISO file and boot from it. I tested it this morning with 3 things I carry around myself (debian-live, debian-installer, freebsd release installer), and it worked. 1 stick instead of 3, and I still have the remaining exFAT partition for other things. And a spare encrypted partition if I wanted to (I don't).
Regarding bugs -- it works or it doesn't for your distribution. I think it's remarkable what this, seemingly single developer, has achieved over a bit more than a year[2].
[1]: https://en.wikipedia.org/wiki/UNetbootin
[2]: https://github.com/ventoy/Ventoy/commit/2090c6fa978999d4ef1e...
[x]: don't get me started with Intel SSD firmware "bootable" images.
I'm not sure why a piece of software being built by one person is sketchy but ok.
<https://unetbootin.github.io/>
<https://en.wikipedia.org/wiki/UNetbootin>
This is barely a year old and comes all, besides a handful of comments, from one account https://github.com/ventoy/Ventoy/graphs/contributors
Personally and subjective this rings quite some alarm bells for me, seems just a bit sketchy and in any way really young, so not as much time out on the field and thus possibly not as much bugs shaken out...