What's the difference between 36_Beta-1.4 and 36-1.5?

What is the difference between
Fedora-Workstation-Live-x86_64-36_Beta-1.4.iso
and
Fedora-Workstation-Live-x86_64-36-1.5.iso
?

I’m asking because using editliveos with the --script flag works fine on the Beta image, but on the final release it always throws this error:

Error editing LiveOS : 'Unable to unmount filesystem at /var/tmp/editliveos-7ux8rw5b/install_root/run. The process using the imgcreate module, or one of the libraries used by that process, leaked a reference to the filesystem. Please report a bug at <https://github.com/livecd-tools/livecd-tools/issues>.'

Are there any major differences, especially in terms of layout, between these images?

In this case beta img is more buggy and less stable then stable one you can use beta if that works for your issues there you can always update and to the stable system.

For my use-case I only use these images as live images so I can’t really update them. Are there differences beyond different package or kernel versions between these images? A different file system maybe or different permissions on the squashfs, rootfs or or something like that?

I don’t know about that but as far as i know they are almost same just slightly more stable and some more newer packages as in beta there are gnone beta packages present but in stable only stable packages are packaged.
But i don’t know why you always use it as live img you can for sure but for live img i think are better option like tails or kali-live etc.

But if beta img works for you you can use it with no issues.

Here is how isos are composed.

https://docs.pagure.org/releng/sop_composing_fedora.html

There shouldn’t be any changes regarding file system. All that changes from beta to RC is updated packages.

https://docs.pagure.org/releng/