24.5 brought a couple of what I would call, major improvements.

The first being the way Xara now asks how you would like to handle text when you edit it in a variant. This isn't exclusive to Blocks, but I think it's important enough to mention.

The second major improvement is how we can now adjust the width of the Flexgroup manually. This has an added attraction as we can now have multiple Flexgroups in the same Block. Simply shrink the width of the Flexgroup to half, or less than half, the width of the Block, copy it and paste. I can't think of a practical use for this, but it's nice to know I can if I want to.

Another fix was a feathered object can now be added to a Block. This had me interested as I have moaned about not being able to add tables, bevels, contours, moulds or 3D objects...and I still can't. Feathering was as far as it went.
Adding to the list of still-to-be-done: snap to object. This seems to have a life of its own. Quite often two objects DO snap, but without a visual aid, they just lock. Sometimes they just don't. At all. I have no idea why it sometimes half works, and sometime not at all.
Groups in a Block can't be ctrl clicked and moved. The ctrl object leaves the group completely.

I love the fact I can now (easily) adjust the width of a Flexgroup. I also like the fact it's harder to stretch said Flexgroup beyond its limits. Although all I have to do is make an object the same width as a Block, then add a glow shadow or give the object a line and we're stretching the Flexgroup beyond its boundaries. This is an observation, not a moan as it's now a doddle to make it behave.

A few small steps, but not all updates can be ground shaking.