Alacritty should support window decorations on wayland. What compositor are you using? Note that alacritty prefers server-side decoration, but some compositors don't implement it like GNOME's mutter[1], in that case it will draw its own decorations.

1: https://gitlab.gnome.org/GNOME/mutter/-/issues/217

I'm using Gnome. And alacritty draws it's own decoration. But they are out of place and more importantly they don't behave like normal windows. For example to maximize a window normally I double click the title-bar but alacritty (I think it's winnit's fault) doesn't react to that. The button placements in the titlebar is also weird and needs me to be really accurate to click the close (x) button.

Yeah, you can blame CSD for that and mutters lack of supporting SSD.

A quick glance at the docs tells me this implements its own multiplexing all the way down, as opposed to integrating with tmux like iterm2 does.

The downside is that this requires installing the multiplexer on the remote machine, whereas iterm works with the much more prevalent tmux install.

Not sure what this means in terms of performance, I've never had any issues running remote tmux in alacritty or in iterm (via `tmux -CC`).

I don't have any use for running tmux locally, but I would sure love to be able to have actual windows for remote sessions (I use i3 and would prefer to manage all windows through that).

FWIW, wezterm is very slowly building support for `tmux -CC` as well: https://github.com/wez/wezterm/issues/336

tmux + alacritty seems perfectly fast for me, tmux's buffering really shouldn't slow anything down