Wouldn't it be beneficial to bounce a track to a new track once you are satified with it then turn off the plugs and archive the original and use the bounced version with the committed processing for mixing? Wouldn't that free up a lot of processing the DAW and CPU have to do and minimize snap crackle and pops, phasing etc. I'm wonder how many of you may be doing this. I don't see a downside except the number of tracks you'd have. Your thought's..

Bounce and archive (you do not need to disable FX. archive is enough) will reduce CPU and memory use. Increasing mixing latency will also reduce CPU load. BTW, freeze does essentially a bounce and archive without creating a new track.

Depends on which I effect. Wouldn't the whole point of mixing (apart from leveling) be to adjust at least compression and EQ per track?
I guess you could bounce things like a Guitar Rig amp sim on your guitar track, or a phaser on your keys or something.

This is something I used to do a lot on my earlier systems, but these days, for me at least, I don't feel the need.
 
My system can cope with whatever I throw at it, but having 32Gb of RAM helps enormously.

Once you are ready to mix you will probably want to change some of the processing fx ; that's part of mixing

To commit to a track earlier won't help you get the final results you want.

Bouncing, turning of FX, and archiving is much better achieved in a single click via SONAR's freeze function. However, aside from heavy soft-synth usage and, assuming you are not mixing hundreds of tracks with FX, if your computer is choking on merely multiple dozens of effects I would look at:
 
1) evaluate your current computer's performance to see if something is bogging it down outside of SONAR related processes.
2) upgrading your computer
3) increasing your latency during mixing

One thing I do is when I get my drums and bass locked in the way I like them, I bounce them to a stereo track, then freeze, archive, and hide the drum & bass tracks. When I'm ready to do a final mix, I bump my latency waaaay up and go back and make those tracks live again. It frees up CPU for the recording/overdub process and cleans up the screen for editing comping until you're ready to mix.
 

Often if I have an instrument with several effects and I am happy with it and consider it finished, I save a copy of the project under a slightly different name (e.g. <project-name>_PIANO if the instrument in question is piano).  Then I export the instrument to a WAV file and import it into the main project.  I keep to "piano" version of the project in case I subsequently change my mind and wish to revisit it.

One of the main reasons I started doing this was to free up UAD plugins when I only had a UAD-1e, which can only run about 7 or 8 plugins at once.

Mosvalve - freezing has been my practice for stuff I know is going to be a drag on achieving low latency playback (I use low latency for recording new tracks). Some soft synths can sound fantastic at generous latency, but start complaining at low latency. For me, freezing those kinds of tracks is a real convenience and still sounds great.