Yes, Mark implemented the part that lets you set it up and then sat down to start working on the part where the second factor token is actually generated and sent... and then realized that we actually have eight billion different ways to log into the site, all of which but one are part of a workflow that also lets you do another thing (change a setting, make a comment, post an entry, etc) and there was a lot of refactoring that needed to be done and some really gnarly workflow issues he was going to have to solve, which neatly looped back to the existing Problem That Is Blocking Literally Everything We Want To Do of "we need to finish this damn modernization/conversion project first". I really cannot overstate the degree to which finishing this damn modernization/conversion project is the albatross around our necks: it's tedious, it's deeply unfun work full of a lot of impossible decisions with no clear answers and no good compromises, it touches literally everything, and we have to handle it like nitroglycerin because of how much it can mess up people's use cases and workflow. It is the hellproject and we are so, so ready to be finished with it already. So, so many developers have taken on a part of the project with great enthusiasm, gotten it 90% done, and the process of fixing all the edge cases and tweaking all the tiny details burned them out so badly that they never want to touch another part of it again.

(The good news is that I think the inbox and the shop are the last two big user-facing things to convert, and the last 20% is all the tiny little elements that are loaded onto individual pages but aren't separate pages of their own. That will be a different type of nitroglycerin, but it will at least be a novel problem.)

Anyway: yes, it's a thing, we really want to get it done, it's just being blocked by the same thing that's blocking everything else on our "it's a thing and we really want to get it done" list.