Requested feature overview description.

Add a "Lock Rating" option to the mode dropdown menu for Contributors.

Why would it be useful?

The option to switch to a rating-lock mode is currently only available to Janitor and above. As a result, Contributors need to manually load every post and click the Edit button to lock their ratings. Giving them the rating-lock mode would expedite the process of using site tools that they already have access to.

What part(s) of the site page(s) are affected?

The posts page: https://e621.net/posts

Is it a good idea to be able to lock a post's rating by looking at its thumbnail? It can be pretty easy to misinterpret something as being explicit or not from the thumbnail, and should get a closer look to be sure.

watsit said:
Is it a good idea to be able to lock a post's rating by looking at its thumbnail? It can be pretty easy to misinterpret something as being explicit or not from the thumbnail, and should get a closer look to be sure.

I mean, to be fair, Privileged members already have the mode option to give safe/questionable/explicit ratings from the thumbnails.

watsit said:
Is it a good idea to be able to lock a post's rating by looking at its thumbnail? It can be pretty easy to misinterpret something as being explicit or not from the thumbnail, and should get a closer look to be sure.

In addition to what TheGreatWolfgang said, posts that seem ambiguous can be clicked to see them in larger resolution. There are also some user-side scripts and extensions that can expand the post on hover-over (I don't personally use them, but I've seen others use them). The rating-lock mode is already offered to Janitors, although Janitors and Admins generally have their hands too full with the approval and flagging queue to worry about less-important tasks like rating locks.