CPU Efficient alternatives to play~ ?

hi,

I'm building a granular synth thingie that uses poly~ to have a dozen or so play~ objects read out a soundfile at different points in time. my issue is that play~ seems to use the same amount of CPU no matter if it outputs 1 or 2 channels of a 2 channel buffer. I would expect that reading only 1 channel would roughly be half as cpu intensive, or not?

previously, I had used the xplay~ external, mainly because it uses about half the CPU for reading 1 channel compared to play~. But xplay~ isnt UB yet, and this is important in my case.

So what I'm wondering if there's a playback object or external that does the follwoing:

- Is Universal Binary
- Offers interpolation to avoid aliasing (so no "index~")
- Doesnt waste CPU when reading only one channel instead of two

and

- Lets one specifiy which of the two channels of a two channel buffer to play ...

thanks for any advice
axel