So ebay apparently learned a new trick, that old dog.

Previously, any orders containing multiple items would combine weights and go with the biggest box of all items to calculate the shipping -- they assume you are going to put them in one box and that that box must be the same size as the biggest item 🤨

Since I prepackage everything and use boxes matched to the sets (with some room for a wrap or two of bubble wrap), I'm always going to need larger boxes and usually find myself in volumetric pricing territory.

So, I've disabled combined shipping and just refund the difference to a buyer if they want me to try to combine boxes and reduce shipping.

Well, today I get a multiple-item order and -- I'm not sure how -- but ebay actually came up with a new box size.  It is much larger than any one item.  It seems to have figured out the longest dimension at least and made sure the box was that long.

Probably won't help me much since I still don't trust it -- it doesn't know what box sizes I have sitting around -- and sometimes it is safer to send two large sets in separate boxes anyways to avoid crushing each other.

But worth noting that they are at least trying.

Now, let's see if they ever learn that I'm not going to combine (after specifying the items don't qualify for combined shipping) just because it is through global shipping...

Well, after packing the order, I gave ebay too much credit.  Seems they still went through the dimensions of every item and just picked the worst-case dimensions.  I.e. if I had sold two items measuring 17x1x1 and 12x12x12, they would have used 17x12x12.

Their final calculation suggested a box measuring 1547 sq-in.  The total volume of all the dimensions in the order was 5083 sq-in -- the dimensions given to ebay shipping to compensate for outside box dimensions rounded up to the nearest inch.  The actual box used was 2880 sq-in -- much smaller than I would have usually used because the customer was focused on reducing shipping costs and didn't care about box condition.

So, ya, I take back my observation.  Looks like they probably haven't changed anything at all -- I just haven't had such a large order with such a varied selection of box sizes.