How about making it so that logging in keeps you on the same page you were previously on, or alternatively navigates you back to it. Old.reddit.com does that, but here it goes back to the main page which is confusing.

I also very much dislike the behaviour of the main page, but I think that is a federation-wide style decision. Basically it mixes up the posts from all the different communities that you subscribe to or whatever. I think Facebook works something like that too (idk, I don't use Facebook). I find it completely disorienting. It means instead of focusing on some single thought or catching up on what is happening in a community, you see a never-ending stream or "feed". I have heard in many places that Facebook messes up people's minds, and I suspect this is why. I hope the UI can be reverted to show just one community at a time.