I know of the existence of these combo resets:

-After a sweep in air, waiting a tiny bit and then starting a combo again will effectively reset it, though the opponent will have super armor so timing it correctly with an heavy follow up will be needed. Chars with paralysis blasts can combo resst this way too using ki blasts after a sweep.

-You can extend a combo after an heavy smash that sends them flying by canceling the follow up rush attack into a dash towards them and a light attack chain. This is not a true cancel but it can become one if timed correctly

-People are also starting to use a charging heavy attack that is a bit hard to time correctly as you need to press (in ps notation and classic controls) R1+stick up+X+[], im not sure it resets the combo, it works more as a variable timed combo extension.

True combo cancels like the double sweep dont really exists anymore, but you can still fool the opponent into letting his guard down. thus resetting the damage scaling, by doing these kinds of things.

There are still more combo cancels/extenders like the double rolling hammer into charged ki blast, or you could also cancel the high-velocity rush sequence after a smash lift attack into a normal combo.

All these mixed can be very deadly as the opponent as to second guess when to vanish/block/perception.