I certainly hope that there are technological improvements that we can take advantage of that have occurred in the past decades (in manufacturing, modeling of pressure vessels and chemical processes, etc).
Mass to mars is incredibly expensive, it's worth spending the time and money to optimize whatever equipment you are sending there.
Under STP and 1G, yes. Mars isn't at STP or 1G, so they can't assume that the Earth-standard machinery will work without modifications. This is a reasonable thing to experiment with.
And contemporary off-the-shelf components that perform the Sabatier process aren't probably meant to operate outside the Earth.