Read the neighborhood
A Producer is easy to read on its own. Support makes the picture less local: a part can matter because of what it changes elsewhere.
Look at the group around a possible support position. Which parts would it influence? Which would remain outside it? A junction is a proposal, not an answer.
Coverage has a cost
Every support core occupies a socket. The machine gains an influence and gives up another possible use of that space.
The balance shifts as the surrounding cores develop. An arrangement that once asked too much of a support position may eventually justify it.
A line is another kind of neighborhood
Relays invite you to read across the board. A row or column can acquire a purpose that is difficult to see one cell at a time.
Local arrangements and longer lines need to coexist. Their intersections can make a position unusually important, or make the whole layout harder to untangle.
Keep the comparison honest
Use the preview to change a position while keeping the rest of the machine steady. Read the projected output before applying the layout.
Then revisit the result after the machine changes. A configuration can be right for a particular moment without becoming a permanent rule.
A full board is still an open problem.