These are the destructive FX that will change the audio for good, these can be all applied as non destructive realtime FX, this way you can modify them at any time you like and it will leave the original wav file intact, they are applied during playback and render. No wav's files need to be written as back up, just the project file. Fade In Fade Out Gain Pitch Shift that can all be done directly on the audio item. When it's playing back the RT/RD files direct from source it will use dllelastiquePro.dll this will pitch shift or tempo stretch any of the source files in realtime playback.
So it's not creating any new wav files, you down mix your song direct to stereo wav mp3 etc..
Only if you drag render export any track it will do the same and render all the realtrack section of the source files together into a new wav.


Biab Track Injector for Reaper
Free Biab Chord Picker Tool