Yesterday I placed an order for another 2 wills. Finding one was straightforward, finding the second despite filling in all the boxes with the correct information (name, dates etc) was tortuous. Finally by deleting all the optional boxes & changing the probate date to the year of death the correct page appeared - dated as the year I had been inputting in the first instance as the date of probate already verified from the page image on Ancestry. Sigh!
I can't see that the boxes for extra search fields can do anything for pre-1996 probates. For the recent ones, those data items are in their database. For earlier ones, they only have the images for each year, and those are indexed by year of probate. I don't see any evidence they have captured the contents of the in digital form, though they might have a project to do that.
So when the resurrected site appeared with the date on the first page labelled as "date of death" instead of probate, I was sceptical. (Though in fact I didn't at first notice!) I suggest assuming it's still date of probate we should enter here.