The easy part: The tilt mechanism of the table saw stays intact, so that you can continue to use that to angle your cut.

The normal operation of the height mechanism is just to raise and lower the arbor with that lever. Since the circular blade is intended to turn, the usual operation of the saw allows the blade to rotate freely. Just securing the arbor (for example by holding onto the belt) doesn't maintain the blade in the same position relative to the table top as the lever arm is raised and lowered. You can adjust the belt each time a height change is made, but it's much simpler to incorporate the new lever arm to do that adjustment for you automatically.

My experimentation with this arrangement shows that your basic consideration is the length of your cut:
Long cuts (across wide stock) requires lower blade angles, since you have more wood under the teeth at any given time.
Leave the wood over the blade when adjusting for subsequent passes and raise the blade just enough for the lower end to be short of the maximum height of the kerf. This keeps you from cutting too aggressively and also avoids deforming the blade by trying to cut too much at once.
This tool would also be useful to make repetitive, starter cuts, when a cut deeper than the capacity of the saw is planned, so that another saw can be used to manually finish to the final depth. It just starts your cut at the right angle and correct location.