This plugin bypass mode is great in Wavelab, I hope it will be added to Cubase one day!
New “Bypass Original” switch
This option is only available from the Master Section plug-ins for VST plug-ins and from the plug-in command bar. When you open a plug-in you can see a new popup menu that enables two choices:
• Bypass Effect: the standard bypass, to play the unprocessed signal
• Bypass original: this causes the difference (process signal minus original signal) to be played
This new mode is especially useful for plug-ins such as Declickers, as it allows monitoring only the removed clicks. This is also useful to monitor what an EQ really does to the sound.
Please note that certain (rare) plug-ins cause a phase shift in the processed signal. In that case, subtracting the original signal will not cancel it (or only partially).
I REALLY think that would open some ears. Me for one, I’ve two that need to be redrilled by a tool like that! 
And it’s in s t e i n b e r g Wavelab, eh? Excellent …
