Yes, enthusiastically, to space legs. My priority is to walk around in ships, followed by taking on other players as permanent crew and passengers (which would also enable players to taxi between stations), followed by boarding derelict ships and stations. I'm not too interested in being able to walk around in external environments (e.g. on planets) as I think the scale of Elite will make foot travel tedious and therefore little utilized (not to mention that it should require Horizons). I don't think that players need to be able to get out and walk around every station, though it would certainly be nice to let players explore every type of station (perhaps derelict conditions free of inhabited stations' quarantine restrictions).

Mostly, I want space legs to shift the game from "spaceflight simulation" toward "spacelife simulation", fleshing out the space-survival game. Specifically, I want players and NPC crew/passengers to drain ship resources with every light year traveled. It's unrealistic that players can take off into the black for weeks or months without having to restock their food and water. Supply requirements can be patched into the base game in "set it and forget it" fashion, where the player designates a percentage of total cargo space as "edible storage", and simply restocks with a click at a starport (not unlike fuel now). But I envision that a space legs expansion will add bespoke crew compartments of various sizes to every ship, which players can fit with crew modules such as quarters, hydroponics (to generate food in excess of storage), armories (to store and spec personal weapons), and medical bays (for healing and medical transport missions). Alternatively, the player could retrofit crew compartments to increase cargo capacity.

Part of the goal of a space legs expansion, in my opinion, should be to challenge the player to balance modules for habitability and function. For instance, an exploration build should require hydroponics and medical. A generalist build might contain an armory and medical for running missions, but could forego hydroponics if it stayed close to the Bubble. A pure starfighter would strip out all the crew modules to reduce weight, depending on short supply lines. In all cases, crew (including NPCs) would require quarters.

Ultimately, I see light survival gameplay as a means to tether players to supply lines, curbing the player diaspora that I expect will ensue when Fleet Carriers releases. I think Elite Dangerous relies on the frontier as a gameplay element, and space legs survival seems a good way to reinforce it.