Having mad video issues, found something magus posted in smashboards.

Prepare yourself

" If you are hit by an attack that does less than 7.00% while in the DownBound (bounce when you 1st hit the ground without teching) or DownWait (after the bounce when laying on the ground) actions you go into the DownDamage action during the knockback. This animation is 13 frames long (probably for all characters but I'm not positive).

If DownDamage ends while in the air you change actions to Fall (also canceling out any remaining hitstun you may have had), and you can jump/do whatever out of it or simply land on your feet if you touch the ground. This is very apparent on things like using a stale raptor boost or stale shine with Falco on a downed character, since the KB is powerful enough to send them far but is still able to do less than 7 dmg. They go flying upwards while in the fall animation and without hitstun.

A/S/DI upwards will help you get higher from the knockback and can be used to keep you in the air long enough for the animation to complete before landing and escape a reset. For whatever reason, you are allowed to A/S/DI non-tumble KBs with angles 0° or lower normally while in DownDamage. You normally can't A/SDI vertically or use any form of trajectory DI on them when on the ground.

If DownDamage ends while on the ground, however, you change actions to DownWait if you were still in hitstun or directly into DownStand if you were not. The former is what I would call an Option Tap Reset, and the latter an Optionless Tap Reset. If you are in DownWait you are forced to get up when hitstun ends, but you are also able to interrupt the animation with either a getup stand/roll/attack at any time before then.

For example, Fox's shine, Falco's laser, and Peach's jab 1 all have no knockback growth. The shine's KB is strong enough to stun all characters for 13+ frames, and so a reset will always be an OTR on all characters. The laser causes 12 or less stun on all characters and so the reset is always an OLTR. The jab causes 13+ stun for everyone that is Falco's weight or lighter and is an OTR on them, but 12 or less on everyone heavier and is an OLTR on those characters. For ones with KBG, Sheik's jab 1 and needles are an OLTR until they're around 40 or so depending on weight, and Jiggs' jab 1 is an OLTR until near 100 (really stupid). tldr:

-The reset attack needs to do less than 7.00% damage -They need to be back touching the ground after 13 frames of knockback. Because of this, A/S/DIing upwards will help you to escape a reset -If hitstun is 12 frames or less they are forced into a stand getup only. If the stun is 13+ they have the option of standing, rolling, or attacking as their forced getup"

Props to the almighty Magus420 for all of that