we do already have mom_hud_menu_show ruler_menu
(or something along those lines, it'll autocomplete after the first command) which lets you measure between two points. this doesn't have all of the functionality of what you're talking about but it does a good bit. perhaps we could expand it to allow for permanent lines (tho thats what this sorta will do https://github.com/momentum-mod/game/issues/315)
modifying the command in that menu to actually show distance per axis could be nice, right now it just measure the length of the line.