What's difficult is reading threads, or more broadly replies. But single posts? Absolutely fine, in fact it's about the only thing that is totally functional without being logged in.
I only get "See this post in the app" with "Use the app to view all comments and discover more posts." with only an "Open X" button in that dialogue.
There is no button to disable this. I can only see the text by using "Page Zoom" buttons on my phone, so it's really not worth it.
* Looked at the top-right corner of that popup.
* Then, scan upwards from that corner, maybe 1cm above it
That’s where the x to close it is, for me. I’m not sure if it is screen specific or what, if it is a bug, etc. It doesn’t seem like a UI anyone would build intentionally but then, who knows?