How crippled does the device feel? Is it usable? The two things you mentioned wouldn't be a problem for me. I've been considering enabling it for a while but wondered how restrictive it will realistically feel.
1.) FaceTime calls from people not in your recent calls will be blocked with a silent notification. Sometimes I don't see it for hours
2.) Incoming iMessages will be stripped of Live Photos and document attachments
3.) Using Starbucks in a browser did not work until I disabled Lockdown Mode in Safari for the domain. Fortunately these exceptions are easy to make and persist
I'm not a target for state-sponsored attacks but will generally trade usability for security when reasonable.
(3) is weird. Conceivably it’s using wasm (I recall many years ago wasm had no interpreter mode, no idea of current state), or webgl (which seems plausibly like something that would be blocked)
Not. And yes.
I did some analysis of it when it came out to figure out what all is blocked and such: https://www.sevarg.net/2022/07/20/ios16-lockdown-mode-browse...
Animated gifs in text threads don't animate - which, personally, I consider a feature.
And webfonts aren't loaded, which means a lot of forums that load icons as a webfont have a lot of squares instead of arrows for reply and such.
You can disable it on a per-website basis, and I don't do much in the way of facetime and such, so I've not really noticed it. It does remove a LOT of complex attack surfaces, though, which is worth a lot.
The only smart thing to do if you are such a individual is to not have a smartphone at all otherwise you are 100% going to be successfully attacked because every commercial smartphone is trivial to hack for a dedicated threat actor. In addition, you should never purchase a smartphone from any existing smartphone vendor for the foreseeable future regardless of what dangerous lies their marketing spins because all of their security organizations are structurally incompetent with respect to protecting against sophisticated digital threats. It would require a wholesale replacement of their security leadership, technology, and ideology for it to even be possible to actually protect against sophisticated digital threats.