Leap smearing is amazing exactly until the moment you need to know whether you're leap smearing (because your seconds are 1.0000116s long, or the reverse). That instant, it turns from amazing into the worst godawful mess you can imagine.

Leap seconds can be stored and communicated, if you need it you can do the work and get it. Leap smearing, you're shit out of luck, especially if you're a developer and need to deal with systems operated by others.

If you're sure you'll never cross that moment and need to know you're in a smear, go ahead, it's great. Otherwise test yo' stuff with leap seconds and get bugs reported & fixed.