I read the threads and never saw mention of this. I'm guessing the main argument against fastfalling at any time is that it makes edgeguarding dairs extremely risky since you would fastfall whenever you initiated a dair.
However, if you make it so that pressing down cancels the jump and initiates a regular-speed fall, you could do aerials safely off the edge, with the option of pressing down again to fastfall them.
As far as I can see it adds depth.
-more shield pressuring options
-more short-hop height options
-a lot less 'floaty'
-rewards more skilled players with better control over the height of their jumps
It also allows you to attack at times when it is currently impossible. Suppose your character is the asterisk, and the flat line is the stage.
*
_____#__________
You cannot attack in this position. Here's why:
Option 1 - you fastfall and attack. The timing on this will be predictable because your jump ends at a certain time. Your opponent can anticipate and punish.
Option 2 - you double-jump, then fastfall, then attack. This is also predictable because double jumps last a certain amount of time, and it's game protracting, because they're slow and floaty.
Option 3 - you attack right away in the air, to protect your position. This forfeits your chance to attack again when you hit the ground, and you have to DI or airdodge away from your opponent. The ending lag on your first aerial leaves no time for a second.
Messing with the short hop height might make it easier to pillar and juggle, but it does nothing for you when you full hop.
This is a problem the series has always had. I don't recall any laws saying we can only add things that were in Melee. We can make more creative improvements than that.
