Oh, I have no excuses.  It was good old fashioned negligence.  I had a good run with the GPU's I was using in my rigs (this was back when that was still a thing), but they were going the natural death of all GPUs, and summer was heating up.  Also, the switch to ASICs was just beginning, which I didn't care to invest in, and in a technical sense the pools were all so big that I didn't think I was *needed*. 

So I quit mining, and completely forgot that I had the pool set to autopay to wallet at 10 BTC.  Days ago, in a bit of a pinch, I thought to myself "You know, I could have sworn I had half a btc on one of these drives..."  Actually, I had 28.78, with 20 linked to a single wallet.dat!

Anyway, I set the automatic payment threshold to just a tiny bit below my current balance, and waited.  Nothing after about a day.  Pressing instant payout gives me a "please_wait!" error.
I sent them an email, also.  Nothing yet, but I'll certainly give him a little while to notice the situation.  I'm quite sure deep is still around, albeit on another alias.