Audio Clip Waveform Rendering “In the Way” – Tracktion Forum

As far as I can figure, it is an option for reducing cpu load. Waveform allows clip based fx, which require proxy files option to be on. I see it as a non destructive render to save the application processing them in real-time. It also can be used with pitched/time stretched audio for the same reason, and also with audio clips that don’t match the project sample rate. In some of these cases it very much affects the resulting playback sound.
The drawback is exactly what you posted in the original post. You can easily turn it on or off at clip level as needed when making quick edits. I have it set to off, globally, and turn it on when needed, as I do a lot of slicing and resizing samples.