From that screenshot it does look like TIM should stop refining Nickel since it's at quota and other things are below quota. So it's possible that's a bug, but my guess is that you're actually very slightly below quota on Nickel as well, i.e. 656550 / 657450 which gets rounded to 657K/657K. I haven't yet come up with a good algorithm to assign ores in proportion to how far below quota they are, so if both Cobalt and Nickel are below quota (by even a tiny little bit), TIM will allocate them evenly and 8 Arc Furnaces each is the expected result.

So the first thing I'd suggest is to upgrade to the latest script version if you haven't already. That includes an update to how proportional quotas are calculated which will tend to make them a little more stable, and that might help your setup to quickly reach your Nickel quota so that it can stop refining Nickel and switch them all to Cobalt.

If that doesn't work, then try adding "debug=ref" to your script arguments and tag a panel "[TIM DEBUG]" to get some more detailed output on what TIM is thinking when managing your refineries. That might give a clue to what's causing this situation.

So, it looks like you're right about being RIGHT on the cusp - TIM is also leaving an assembler running that's using a little nickel (along with things using a LOT of cobalt), which is making that situation stickier than it should.

Regarding algorithms, maybe just have a couple thresholds?
1. Any material at 10% quota or less? Divide all refs/arcs amongst that list if so, and done.
2. Ditto 25%
3. Proceed normally.

?

hey taleden, any chance you'd list out all the different debug posibilities, I didn't know you could make the debug=X statement.