Before all, a blade guard needs to shield my fingers from the spinning blade but not only. It also should provide a satisfactory dust collection. I tried some shop-made components that were safety efficient but never reached the effectiveness of the origin one from the vacuum perspective. On the other side that manufactured device holds two drawbacks. The first one doesn't allow for quick removing and replacement of the guard as the rotating part covers the lock mechanism. The second one is also related to that shroud. Probably due to the scoring unit the blade housing protrudes so much that it is always remaining in the way and hiding the cut point. Using the scoring unit one time out of hundred I made the decision to only keep the nozzle.

The characteristic design of that patented nozzle didn't let me free about the knife shape and the quick remove-and-replace needed a groove allowing a smooth move. Although the riving knife is the key element about kick backs I wished one closely fitting the nozzle recess. Whatever the direction the guard shouldn't move after clamping and in fact it worked far better than expected as if riving knife and nozzle were a single component.
The second step was easy to achieve. I replaced the round head bolt and thin nut with a bristol lever and a standard nut. Then added a spacer because of the origin recess bolt.
The tricky work was to move the shroud axis from the rear lever to its front and most of all how clamping the nylstop nut into the nozzle. A thin aluminium strip shaped to accommodate three sides of the nut pushed that one against the bevelled partition. Cut out from spare plastic transparent material and epoxied the shroud needed to stand alone whatever its location. The countersunk head screws in conjunction with their nylstop nut filled the function. Like the origin guard I added two wooden strip I stuck against each side rather than screwing them. Anyway if something bad happens the thin transparent side would probably break at the same time.

Is the quick replace and remove mechanism enough efficient ? Obviously not. If it was everyone would use the manufactured overhead saw guard provided with the combination machines. When removed the saw guard need to stay close to the operator. Here is my solution where push stick and saw guard get along with the rip fence. Thereby releasing or replacing the guard means : unscrewing the clamping lever three quarters of a revolution then lifting the guard and pushing it onto the other base. No other operator's movement is needed.