I ran a custom updated scripts to add notes to parts. This left the WTPart is a checked out state, about 11K parts now are on my checked out objects table. Yes, I could have improved the script to check them in automatically but here we are. How can I get them all checked in? You cannot do it from the checked out objects table, there is only undo-check out mass action.
Solution was to use a search results, querying on Parts checked out to me. From that table, there is a Edit multiple objects mass action. You can do them in batches from the popup UI and check them all in.