Ok, so first, there are many, many, many, many problems with editing blocks. But apparently it’s all fine because it’s been like this for 20 years, so no need to change, right? 
Second. If I have multiple nested blocks, and want to edit one, I have to click in this list:
But when I want to edit the next block, how do I do that, without closing the window and starting all over?
Don’t panic, just wait another 20 years. 
// Rolf
Hello - I am confused - why would you not just click on a different block in the same list to edit that one?
-Pascal
Because yesterday when I posted this thread, that did not work. It was always locked into the first clicked nested block and never would accept editing of any other block until I closed that window.
Today, however, what you describe does seem to work… we’ll see for how long, I guess.
Here we go. Don’t ask me how I triggered this bug, because I was working fast… (until I wasn’t working at all, apparently):
Quitting out of block editing and then attempting to drill down again solved it, but it keeps happening!
I don’t understand why you can’t just keep double clicking on the blocks to drill down.
(Also, as to why I’m using wireframe mode, it’s still because of this.)