unrendering clips in montage

I have just moved to wavelab 7 from Samplitude. I am trying to figure out how to unrender clips in the montage. For example, the way I prefer to work is by applying my plugs to the clips and render each individual clip at the source sample rate and bit depth and having the rendered file replace the original in the montage view, saving dsp so I don’t have so many plugs active on each clip of a 12 song album. After working my way through all the clips, do my spacing and track cues and create my master. However sometimes I may want to process something different on one of the first few clips. So, my question is can I select the clip I want to work on and somehow unrender the file so it will go back to the original source file and have all the plugins be active again? This was very easy to do in samplitude, clips in wavelab are called “objects” in samp. You could just freeze them which is basically a render and unfreeze them at any point to tweak whatever you would like. Is this possible?

In WaveLab, from the Render dialog, you can render the desired clips and replace the undelerlying clips.
But you can’t unrender, or only via the Undo function.

Does wavelab use processing power for all the plugins on clips all the time or only uses the processing power for playing back individual clips? If it is only processing the clip you are currently working on, I should be able to use my mastering plugs on every clip without worrying about cpu power correct? That way I can still keep my workflow as I was in Samplitude and be able to jump from song to song and make tweaks as I go. Thoughts?

WaveLab only use computer power for the clips being played.