To me, just pretend the Mon Cala actually repair it. He can pay for the repair and then cut to him flying in space all shiny and new, then cut to the repairman contacting Gideon.
The Siege doesn’t have any real character development, whereas Chapter 15 has a big sacrificial moment for him. It may feel like a “side quest”, but he’s giving up his cultural values to save Grogu. That’s huge, and very important to the main story.
This. I agree that The Siege is way less important than Chapter 15. The Siege is way more of a side quest that’s un-needed.