This (moving relational ops to server) does not match the definition of local first provided in the article and gives up most of the value prop the article enumerates in the conclusion. I agree that Figma is a candidate to be implemented primarily as a document CRDT, same as the google doc example i already provided.
Well, the problem an index over multiple documents solves for is also not present in the application presented by the article. The plan for an individual trip (or even a lifetime of trips for most people) is not going to exceed a size that can be handled and indexed on the client.