Any shortcuts with control/alt don’t work unless you add keybindings to the config with escape sequences. Some distros give you the config by default but that breaks other things such as jumping to the start of a command with ctrl+a
That is not my experience: ctrl-a jumps to the start of a command. I've not seen any issues with Ubuntu, tmux and fish.
All tmux and fish keyboard shortcuts have worked without any alacrity configuration (that I can recall).
My tmux config adds shortcuts to behave like a conventional tabbed window without any issues e.g. ctrl-n (new tab), ctrl-w (close tab), ctrl-page-up/down to navigate tabs.
