Ahhhh, after reading this, I think the part I was missing is swimming events aren't general w/r/t method
i.e. I'm familiar with track and field - it's "transport yourself X distance, fastest time wins"
With swimming, its "transport yourself X distance using method Y"
And you could have used the methods described in a race where method Y == backstroke at some point, as the requirements for backstroke were such that you just did a couple things quick, then could go underwater and do your thing till you finish...but that workaround is no longer available given the 15m rule.
i.e. I'm familiar with track and field - it's "transport yourself X distance, fastest time wins"
With swimming, its "transport yourself X distance using method Y"
And you could have used the methods described in a race where method Y == backstroke at some point, as the requirements for backstroke were such that you just did a couple things quick, then could go underwater and do your thing till you finish...but that workaround is no longer available given the 15m rule.
(ty all)