It handles requests for forum URLs only. Using cPanel Redirects takes only a minute and handles all redirects. Using .htaccess takes a few minutes but handles all redirects for your site/domain.
I prefer to cover all bases, personally. What you do with your site is up to you.
Be sure to add the HTTPS property to Search Console. Search Console treats HTTP and HTTPS separately; data for these properties is not shared in Search Console. So if you have pages in both protocols, you must have a separate Search Console property for each one.
Here are additional FAQs for migrating pages from HTTP to HTTPS:
It handles requests for forum URLs only. Using cPanel Redirects takes only a minute and handles all redirects. Using .htaccess takes a few minutes but handles all redirects for your site/domain.