I think you covered the reasons in your post. The issue with modifying non-SMT sockets to do this job is the resulting strength of the pins. The flat-leaded ones will put too much strain on the solder joint (peeling effect) when removing the IC from the socket, while machined pins ones aren't easy to bend and chances are the pins will break.
This solution is the proper way of doing it if you want reliable product, want to avoid through-hole soldering process because of a single component you cannot get in an SMT package.