I'm interested in this as well. I currently use fzf and I'm happy with what I've got (except for me syncing would probably be a nice feature to have).
Also: I gave atuin a quick try and found the TUI to be worse than fzf. Why do I need a fullscreen ctrl-r interface? I found that distracting. But maybe that is configurable. I didn't look much further.
And also the default is now to use 40 lines, not the alt screen (has its own drawbacks)
You can set “inline_height”
As long as you're here, do you know if the column showing the amount of time the command took can be removed? I know you can remove it from "atuin history list" with history_format, but I don't see a way to remove it from the inline window.