You're asking a theoretical question. It all depends on the implementation. In studios, all cabling is balanced and carries differential signal. But every gear is internally working in single-ended mode. This means every mixers, pre-amps and amps convert the balanced signal to single ended at their inputs and converts it back to balanced at their outputs. If it was a bad idea, then they would not be doing that, would they? But the thing is, those use high quality converters in a well implemented manner.
If you use a cheap and ugly circuit to convert the signal to balanced, chances are the result will be mediocre. The signal at the output may be noisier and uglier than the input, even if it's balanced at the output.
The only condition for it to be a good idea is that you are guaranteed that the design you use will not degrade the signal. Or degrade it minimally, at least. We can't tell you that every design will meet this requirement. It doesn't work that way.
Oh and the RE272s weren't "designed to be run by a balanced source". HifiMan's marketing department decided to use a TRRS connector as a marketing strategy. Any IEM can be "designed to be run by a balanced source" by simply chopping the jack off and soldering a TRRS jack in it's place. Quite the engineering there...