I’m using the wonderful new _history_complete_word functionality.

Z% echo   
zsh: do you wish to see all 405 possibilities (405 lines)?

Well, no, but I would like to go backwards to the one I do want to see.

If I type up-arrow to that prompt, I get this:

Z% echo [A

It would be better if up-arrow would take me to the most recent echo command, just as up-arrow on an empty command line prompt takes me to the most recent command. Of course, both up-arrow and down-arrow should allow navigation here.