If your a purest than start each rep from a dead stop at the bottom. Allowing a true 1 to 2 second pause while the bar is on the floor, insuring a real dead stop. Same can be applied to the bench press. If your like most lifters you will use the touch and go system, relying on momentum at the bottom of the lift. Dead stop lifts will help increase the natural pull off the floor in a regular DL. Some guy's find this their weaker position. Again, same idea with the dead stop bench press.
If you have used rubber/bumper plates, than a greater rebound from the floor will be gained. Your going to use a lot more weight that way. Is than considered cheating? I do not believe so, just another form of working out. I would also bet that your going to gain more body mass and strength than ever before.
A older method, a lot of very massive strong men did in the past, was bouncing the plates off of heavy planks (probably a couple of 2X6's, 2X8's, etc) for DL training. There was also a devise called a Hooper (AKA the Hopper Lift), also made from heavy wood planks (usually bolted of lag nutted together), that really increased the bottom bounce. The lifter would "catch" the weigh as it can up to around just above knee height. A lot of very heavy weight could be moved that way. In most versions of this older DL training, higher reps were used. 15, 20 or more reps. Somewhat akin to a breathing squat form of working out, with very heavy weight and higher reps. Good Luck.