TI was a fun metric for this puzzle, working out the best split of instructions between decomposing the input and constructing the output was a lot of fun. Conditionals mod 2 or 6 are simple but everything else is very difficult without tracks. So making 1/3 of the output every two inputs was a nice fit.

The first half of this one came together quite quickly, up to making the Silver-Gold-Quicksilver Tringles. But constructing the output was very painful. After a lot of attempts I ended up with a gold atom that needed to move from the front of the output to the rear, but everything I tried was very instruction heavy with lots of swings or rotates. So I snatched the gold from the first input and placed it for the second, expensive waste that only saved 3 instructions in the end.

I couldn't find a neat way to get the output for free, so arm 18 is just hanging out. I guess the optimum is somewhere in the low-mid 50s? But this contest has shown me surprises every week so far.