This will reference the Festool brand as I don't know if it applies to other brands.
The Festool has a built in riving knife. The Festool is also a plunge saw but only to the point of one being able to plunge the blade at the edge of the wood and then driving it across to make your cut. You CANNOT plunge the saw into the middle of a piece of plywood for example...the darn riving knife prevents this from happening.
Has anyone removed the riving knife? I use my saw for plywood 99.99% of the time...I don't really fear the ply binding on my saw as I run it across. I stared at my saw for about 5 minutes and decided to not bother with it at the time.
This weekend I really had a need to plunge it and instead opted for my jigsaw.
Thoughts?