Beta Safety users will probably have noticed the very obvious similarities between Beta Protection and Beta Safety, and that's not a coincidence. Beta Protection (just like Beta Censoring) was borne out of using Beta Safety for a while but finding a lot of things I wanted to change and deciding to build my own vision of a censoring extension.
To reiterate from the introduction guide:
If you're already using Beta Safety, you most likely already have the Beta Safety chrome extension installed. The extension that comes with Beta Safety is perfectly functional and if you're happy with it, there's no need to upgrade to Beta Protection.
Beta Protection is a more feature-rich, but also more complex, alternative to the extension that comes bundled with Beta Safety.
So which one should you use?
To reiterate: the extension that comes with Beta Safety is perfectly fine. It generally works and is enough for most users.
Beta Protection introduces some new features and changes that might make it a better fit for you:
Improved options and UI
In this author's opinion, the original Beta Safety extension's options are a little too function-over-form and (as a consequence of how they're designed) can be a little daunting. Beta Protection aims to provide even more customization than Beta Safety but with a more approachable and understandable design.
Easier customization
Some parts of the original extension were a little more complex to set up than they needed to be. For example, adding new placeholders required you to directly mess around in the extension's installation directory, whereas Beta Protection allows you to import them directly to the extension where it's managed for you.
Plus, Beta Protection allows you to change some settings that Beta Safety didn't expose as options at all, like where your backend is running or what messages the subliminal messages feature would show.
Backend Choice
Beta Protection is designed to work with any compatible censoring backend you like. Currently that includes Beta Censoring and Beta Safety. Whichever backend you choose, and wherever it's running, Beta Protection doesn't mind.
Local censoring improvements
While Beta Safety's backend can be used to censor locally saved images, it's not the most approachable process for most users and tweaking settings for local files is very daunting. Beta Protection includes a guided wizard for censoring your local files, with options to tweak the censoring applied to the files, regardless of whether you're using Beta Censoring or Beta Safety.
Additional features
Beta Protection (at time of writing) supports largely the same features as Beta Safety, but includes a few extras of its own. For example, overrides can be used to enforce censoring options, and Beta Protection includes more fine-grained controls for on-demand censoring, among others.
Fully open source, and more extensible
At the time of writing, Beta Safety is not open source and is difficult to modify even for developers. Beta Protection is fully open-source, published under the GPLv3 license on GitHub. It's also intended to be more scalable and flexible than Beta Safety is, as well as easier to integrate with other projects (like other backends).
Known Issues and Drawbacks
There are also some drawbacks to Beta Protection that you should know before you decide:
Dramatically more complex
There's just a lot of moving parts here. Beta Protection (by virtue of its design) is a much more complex and "heavy" tool than the packaged extension.
In general, this should balance out, but it's worth knowing going in.
Less tested
Beta Protection is a brand new project that just hasn't had as much time in the hands of users as the packaged extension. There might be some bugs I haven't caught yet. No real way around this.
Different performance
Beta Protection handles how it runs quite differently under the covers from Beta Safety which leads to both gains and losses in performance. Experiences will vary but in general, Beta Protection will be a little slower to censor images, but will be less performance intensive doing so.