There are DFN10 / QFN10 test-sockets, but these things cost close to 100 bucks, which I’m not (yet?) willing to spend on this.
If this should work, I would be able to add preprogrammed chips to some SMD DIY kits in the future.
The result: it works :-)
I should add that I had to mill the center hole to correct dimensions, as I apparently oshpark doesn’t do internal cutouts with a small enough routing bit. At least not without making special arrangements.