After finding out that my front wheels were both aiming a little bit outward (together by half a degree), and apparently thus having caused the wear on the inside (inch or so) of the front tires, I had a thought.
However, before I could even utter my thought, the alignment specialist (who re-aligned the front wheels, and who works for a tire-seller) already strongly stated that moving the rear tires to the front was not an option. Drivability would be horrendously affected. (He also mentioned that moving the front tires to the rear wheels doesn't pose an issue.)
Although I trust his sincerity on the matter and I can follow the argument he provided, I still have my doubts whether the effect is significant.
So, is moving the rear tires to the front really a no-no?
The tires are 215/45WR17, the car is front-wheel driven and suffers from understeer. (That last bit of information may be driver-dependent. I don't know.) The tires are directional.
Final piece of information: What I had in mind was switching the wheels+tires, not only the tires.