In a situation where you slide off the stage after an amsah tech due to latent momentum, would it be possible to DI up after the tech, making it easier/possible to survive?
DI is the act of changing your KB trajectory. After you tech and slide off, holding up or down would have no effect while holding in or away would have minimal effect (the same effect you see when you drift back towards the stage after surviving a KO move). The only ways you can make it easier to survive after ground techs is to:
1. Fastfall to the ledge as you slide off to make your character close enough to grab it
2. DJing asap after sliding off keeps you as close to the stage as possible; Jiggs and Kirby specifically should do a jump and immediately aerial
3. Time an attack/taunt right before you slide off; during the animation, the latent momentum continues to be "used up" so by the time it finishes, you will fly off less far
Watch all of these videos:
https://www.youtube.com/user/meleemechanics/videos
I think it's best not to DI the uthrow because getting hit by the lasers from the throw is better than being in pure stun.
It is dependent on the character's weight, but the lasers hitting is usually the only way Falco can true combo from uthrow. If you look at a character like Peach, you can never uthrow bair/uair her if she DIs behind. I think Marth might be the same way, but because he is so much worse at aerial trading than Peach, the direction you DI seems to matter more than whether you get hit by lasers or not. Falco can bair from below in most scenarios unless you get a read on his timing and counter, or if you're high enough to DJ away.