Platform with 2 rails (one on each side) do NOT count as part of a grid (at least regarding O2 and Methane) and DO split a grid into 2 if they are the only connection.
I was building wells on steel platforms, most with Oxygen Sabatier and one with Methane Sabatier processors, on a 3x3 plaform, linked to each other with a rails-on-both-sides platform (not wanting to fall off) and the Sabatiers could not see the tanks that were on one end, except for the one well that was next to the tank farm ...
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