Jamar: Remember you dont need to disassemble everything, just remove head and pistons if the valves have hit.
If head is damaged, then either try to find used one (couple for sale at the moment) and i can help you getting the valves, pistons etc if needed. less than 1000 eur for the parts if head is ok, less than 500 if pistons are ok.
Regarding what you write here: "In hindsight, I realized that the mechanic actually didn’t need to tighten that pulley on the second engine, because it was part of the new engine—but the timing belt had to be adjusted because the original P1f starter-generator was connected to the new block. He definitely used a valve setting tool, though"
1: I'm thinking someone misunderstood something here: If he didnt tighten the pulley, he didnt use valve timing tools, valve timing tool has crankshaft locking tool included so why would he use valve tool without using crank bolt tool?
2: There is no timing belt, starter-generator has serpentine belt and it has auto adjuster, no need to adjust that.
What year was your replacement engine? completely new or used one? Did it have torque mark on the pulley bolt.
Did i show everyone my video? https://www.youtube.com/watch?v=ebsTJw8G_Tc