Exactly. If URL Inspection shows that Google selected a different canonical, another indexing request alone is unlikely to change anything. The better approach is to align the sitemap, canonical, internal links, and redirects where appropriate around one preferred URL. The important distinction is that not every “Crawled – currently not indexed” page is necessarily a canonical loser, so I’d confirm the selected canonical first.
Andrew
Once Google has already clustered the URL under a different canonical, crawled-not-indexed is the leftover on the loser. Another indexing request restates that same cluster choice. Collapse sitemap, canonical, and internal links onto one winner so the next crawl can reopen the cluster.