Near zero latency track switching with identical HLS streams

If I have N number of HLS streams with the identical frame size, codec, keyframe interval, etc. - What would be the expected delay when switching from one to the other on browsers with native HLS support like Safari? Would it be possible to maintain 60fps playback without interruption when switching between streams?

Also, somewhat loosely related - Would anyone be able to recommend a good strategy for manually switching streams via Javascript?

Thanks,

Dustin