I wish it was possible to see the bindings for commands like choose-tree without having to search through the man page every time. Ideally, they would be discoverable from the choose-xxx interface. This could use a binding, or a special entry in the list that shows help in the preview window.

It's not immediately clear what the best binding is. F1 is probably good. The F keys are, these days, hard to access on some keyboards, so it'd be nice to have an additional binding. In Vim mode, ? and h are taken, but c-h and/or c-/ would work.

In any case, the first step might be to have an option to tmux list-keys, e.g. tmux lsk -c choose-tree, that lists the bindings for such commands.

An alternative approach would be to make the docs (currently in the man page) for choose-xxx commands (or for all commands) easier to reach. E.g., they could be reachable with tmux lscm -h choose-buffer or man tmux-choose-buffer or tmux man choose-buffer | man -. This deserves a whole separate FR, though; the main obstacle here seems to be how to do it portably and without increasing the maintenance burden.