The current behaviour of Special:EnableEditRegistration and Special:EditEditRegistration when you submit the form is that if the data is valid, you see a page that only contains a success notice:
I'm wondering if we should also show the (updated) form below the notice. It would look something like this:
The idea being, you're immediately able to see the updated data, and make further changes if you want to. Unsure if it's a good thing to do, though.