What does the latest citra nightly build 4af793c change

I know now there is the side by side but are there any updates on it more fps? How do we know what changes?

You can check the Citra Github https://github.com/citra-emu/citra or wait for the progress reports on the main site https://citra-emu.org/

But do your know what change?

As I’ve said, you can read the Github or (if you can’t understand) wait for the progress report with the info “translated” to the users.
Every commit on Github has a decription listing what each change do, if you can’t understand that, just wait for the report.