This is not a feature of PlayIt Recorder.
What are you trying to do ?
B.U.T.T. will record as well as stream but can't take a VST plug in.
Are you making a processed recording (to use, say for a podcast) ?
Depending on what you want to do, Audacity and processing (or PlayIt Recorder and processing by another application) may do what you want.
For "fix anything" processing (although arguably a bit aggressive) The Levelator is worth a look.
Also this is worth a look:
PlayIt Recorder doesn't work in conjunction with VST Host.
We need it to work.
It used to work fine with butt.