Focus sequencing of >2-step projects

It’s time for a BGS chaining question. (It is always time for a BGS chaining question.)

From the example in the rulebook, several actions can be chained if one person coordinates, but that’s under “coordination with multiple people”. What if the same person comes in at multiple steps, and also it’s Engineering which is allowed to self-sequence for a single person, making this question as complex as possible?

Very concrete example: I want to build an Aether Condenser. I want to build a Bottle and give it to Scrap, who builds it into a Reinforced Preservation Jar and gives it back, and then I finish the Aether Condenser. Is one Coordination enough to ferry the parts back and forth to sequence the construction, or do I need two?

One seems fine.