(edit- I this was written before the last two posts appeared!)
just some more thoughts,
It seems logical that tea will be different depending on where its been "living" in the cake: surface leaves will have totally different conditions to those buried deep in the middle of the cake. They will age differently. - They look different after all!
I understand some manufacturers will put "special leaves" on the surface of a cake perhaps for appearance sake - but also for tea sake (I dunno - like a skin or seal?).
With just these two points in mind it makes sense to me that a good pot of tea will consist of leaves from all over the cake; a nice balanced collection of surface, edge and inner leaf as well as variety of size, shape and type of leaf - at least if you want your brews to be consistent for the cake. One can only achieve this if one breaks the cake up fully and properly.
When I brew up I like to throw into the pot, some single whole leaves, a block or two of compressed stuff, and perhaps some amount of "crumbs". One has less choice when just chipping away a small amount. Having a good selection of broken cake means I'm more likely to prepare my tea better. I'm less likely break leaves in my haste to brew up.
My point is, a full broken cake (probably) leads to better tea brewing.
The question is, how much does breaking a cake up, affect the aging process? How much would 10 years affect tea from a broken up cake vs an intact one? Could it be a broken cake would age quicker and more evenly? Could it be better for the tea, lead to a better drink?
I'm sure tea needs to "settle" for some time in cake form from being manufactured.
Tea in cake form makes a lot of sense of course. Cakes are robust and the tea leaf is protected in travel or piled storage. Once we have them at home though, things are different.
If the effect over time is negative then we must obviously only break a cake if we intend to drink the lot over a short period. Perhaps the key to this is to cut (bread knife?) a proportion of cake, like you would a birthday cake, to break up and drink while putting the rest in storage.
Perhaps I need to get out more and stop pondering such trivia - but I doubt it