Does it support Deforum extension or any other A1111 extensions?

[Godd67]

Looking for a modern UI that have support for https://github.com/deforum-art/sd-webui-deforum

[vladmandic]

sdnext supports some A1111 extensions, not all.
it all depends how any specific extension is written.

Deforum is not supported and given it's no longer maintained (last update was over a year ago), chances it will be are pretty slim.