[tomsem]

I think the 25 at a time thing is about 6 months old. I actually prefer this to the progressive loading thing that was there before).

But then I don’t have a use case to send a bunch of books at once to a Kindle; it’s just not something I have done, or can imagine wanting to do.

FWIW Kindle for iOS lets you download everything in a given collection. Maybe they’ll some day add this feature to Kindle (though it could render your Kindle unusable for some hours while it indexes everything).