Since this subject has come up FYI:

I pulled the oil pan with the engine in. To get to everything I pulled the sway bar and the starter. I then raised the engine via jack on lower trans bell housing. Only needed to raise it around an inch. Additionally the pistons could be pulled if needed.

After that I took the dent out of the pan, it was indeed pressed up against the screen an the oil pressure while not low, was lower than I like at 35 psi. Yes installing the gasket is not as easy as with the motor on the stand but it wasn't an issue

On the speculation front I believe you could change the cam with the engine in, with the pan off the timing cover is easily removed. Using the same magnet I use to retrieve dropped nuts and bolts (it fits in the pushrod hole) to hold the lifters up it may be doable. I also believe it may not save any time over the pulling engine.

Tom