Between the two solutions, "somewhat realistic, buggy, unpredictable" vs. "not realistic but predictable and fast", I'd prefer the latter. However, I think you can do better:

Why not compute the total flow at "build" time based on the heat equation, approximated by a radial basis function where the ...

I joined the forms just to say I've been listening to the "other 2 planets" soundtrack on loop almost continuously while working over the past few days. Really appreciate the work being done on all fronts for this expansion.

Looking forward to seeing the Factorio OST for purchase.