We have now successfully upgraded to v4.3.0-alpha.0+mementomods-2023-12-16 + Mastodon Bird UI 2.0.0rc.
This includes the bugfix with notification sounds among other fixes (thank you @ClearlyClaire @Gargron @renchap for your awesome work, I'm one of your biggest fans, keep up the good work! 
) https://github.com/mastodon/mastodon/issues/28193
This "testing in live" is so that I can help contributing to Mastodon and spot bugs before they end up in the final rc, beta or stable versions. There will be some minor bugs, but the earlier we tackle them the better.
I love running the newest version so I can test ahead in production to the upcoming #MastodonBirdUI versions. I do have my local instance with the production db, but it is far more fun this way and it feels good to have new things.
As usual, please tell me about any strange things you may encounter. We're running bleeding edge after all.
@rolle Seems that my emoji chooser stopped working. I can open it it but if I click on a emoji I want to insert, nothing happens. The chooser just closes.
@turvanen Oops, my bad, thought I merged that fix already. 
This is now fixed. https://github.com/ronilaukkarinen/mastodon/commit/577e190b3be516d461194bc8b0bfd386de5169fc
Please hit refresh.
@rolle Nice, thanks! Now it works again. 