To expand: Early on there might've been some differences in the media rated for double sided disks, but by the time the floppy disk was a consumer item they were all using "good enough" media, and you could hole punch any SS disc to use the other side in an SS drive.

Few cared much really because the double sided drives were clearly the next one you were going to buy even if you hadn't got one yet. And then it wouldn't matter.

A fun trick with some combinations of drive and system involved having a disk that could be read differently when flipped, in a double sided drive. It wasn't viable large scale but crazy people having fun with stupid floppy tricks might produce a few occasionally and hand them around.

(Involved halving or less the sector counts and abusing alignment to interleave one side's sectors beside the others. If you wanted to be evil there were further refinements in what you could make the system report was there that wasn't)

I remember being told this was actually a myth. The manufacturers claimed this to be the case, but the problem was that different systems' drives actually used different sides of the disk, so the disk manufacturers had to verify both sides anyway.