> - some visual artifacts with the gtk menu

You need a compositor. picom works.

For a proper "native i3 experience" I recommend setting gtk-titlebar=false and unbinding tab/pane management keybinds. I already have a window manager, I don't need a second one.

I also had to disable adwaita because when it's enabled closing a shell with ^D closes all open windows, sometimes it leaves an empty window instead.

> - xterm still feel faster to me.

lxterminal also launches 6 times faster, I guess on a slow laptop without a dedicated GPU these terminals are not the most efficient option.

there's a black box after i click the burger menu button.

In case you mean the quick terminal (ctrl+`):

    keybind = global:ctrl+grave_accent=toggle_quick_terminal

doesn't work for me. i'm using i3.

olps, it's macOS only feature.