At one time it was possible to make an edit, put that in the edit summary, go on to make further edits without saving. When returning to the save dialogue, the edit summary would have been retained so it could be added to. This is no longer the case, on return the edit summary is blank (other than the subhead).
This seriously detracts from the usability of VisEd. It is already a step backwards that one has to come away from the page to the dialogue to add the edit summary. For me at least, this means I won't be using VisEd as long as direct editing remains available.
Monobooks/Firefox 39.0/Windows 7