Do any apps allow for controlling “blur NSFW images” on a per-account basis? That would be a killer feature for me.

Try Thunder. It’s available on Testflight as a beta. Here’s the direct link to Testflight. If the direct link doesn’t work, try the first link to Github - the readme should link to Testflight or maybe eventually the app store.

I’ve been using liftoff and has been pretty good.