The proposal covers all of your concerns. If you have a point of contact on the lie at the time of release, it counts as being on the lie immediately after release. No need to jump. In a falling or lunging putt from your knees, no hand can touch the ground in front of the lie. At least one has to land on the lie after releasing the disc and the other has to touch the ground no closer to the hole if it touches the ground at all.
Here's a summary of the idea for every throw but tee shots: "After releasing their throw, a player's next contact points with the playing surface must occur farther from the target than their mark with at least one contacting the lie. A contact point on the lie at the time of release meets the requirement for contacting the lie after release."
The only "loophole" I can see would be a player crouching to do a single foot hop with their right foot starting on the lie. As they come up from their crouch, they release the throw before leaving the ground, hopping in the air with their right foot landing in front of the lie. Their left foot and any other body part if they fell would still have to first tap behind the mark. That contorted throw would be legal under the proposal, but the point is the disc would have been released while on the lie.
You seem to be contradicting yourself here. If a contacting point counts atvrelease counts as after the release, and you have no rules about any subsequent contacts, then your statements about lunge putts (and jump putts and step putts) make no sense.
Your example of jumping forward, releasing, toe tapping, and then landing forward of the lie is exactly functionally equivalent to a step putt under your proposed rule. The step putt contact at release counts for after the release. Then your next foot lands in front of the lie.
Massively confused.