On April 11 a buyer purchased a baseball card from me, paying promptly

He then messaged me, asking if I had any more related baseball cards, and I did. I provided an item number and he bought that as well.
Two cards solid within about a half hour of each other to the same buyer.
The cards were shipped April 14 in one envelope, going letter-mail with a $1.80 US stamp.

All good so far.

Yesterday, (April 30) I got two messages in my eBay message system in-box telling me that item-not-received cases had been opened.
The cards were one day outside the delivery estimates and the buyer was getting antsy. Fair enough. I understand. I responded in a non-confrontational and polite manner, and he responded to me in a non-confrontational polite manner...

"I have been an eBay seller for many years. Unfortunately, eBay now makes it virtually impossible to let a seller know that an item has not been received without a case being opened. I will have plenty of patience with you. I simply wanted to open a dialogue with you. I recognize that the postal systems of both our countries leave much to be desired."

Fair enough. I asked him to give it till May 5, at which time, if the cards haven't shown up, full refund and sincere apologies for postal service incompetence.
Regardless of what happens, this customer will be taken care of to the best of my ability.
But the minute all this started happening, I thought of this new defect system that eBay's trotting out.
Though this was one transaction in every way imaginable, I suspected the eBay system would view it as two. And sure enough, today my 'beta dashboard' screen shows two defects for item not received cases.

If they want to give me one, OK. This doesn't happen often, and I'll swallow that. But here's the thing that really complicates matters.
Many of my buyers have been informing me lately that they are forced to buy each card, one by one, because of some stupidity with eBay's cart program.
It's a fairly well known glitch/oversight/whatever that's been going on for months now, and eBay's likely in no rush to fix it because they get more final-value fees on shipping when buyers buy that way.
What seller has time to phone eBay's customer service people for refunds on final value shipping fees every time it happens?
Certainly I do not.

So... in many cases I'll get a buyer that buys 10 cards or so, one by one. I refund the shipping costs, put them in one envelope and mail 'em off.
For me, one transaction.
But my concern now is that for eBay, these will count as 10 transactions.
I always assumed the new defect system wouldn't bother me much because I don't make many mistakes, have happy customers and do high enough volume to absorb most issues.
But I could see defects adding up in a hurry if a handful of these orders go south.
I'll be phoning eBay tonight to chat about it, but past history tells me it will probably be a frustrating conversation that leads nowhere.