That’s retrigger in the second part you pointed out, you can actually do that in a lot of ways with a lot of hardware (there’s a dedicated button for it on my old MPC; Squarepusher used to do it with the roll button on a Boss DR-660 that was sequencing a rack sampler of some kind) but it’s well integrated with the OT’s workflow and you can definitely get to stuff that borders on simple granular timestretching by messing with RTIM and STRT parameters (RTIM controls the grain size and STRT controls the grain position, but RTRG doesn’t retrigger the envelope, so no control of grain shape this way, and since there’s no polyphony in the OT actual granular synthesis isn’t really an option although there are ways to fake it).
In the first part you pointed out, he’s using delay on the master track set up to work as a repeater, which is also something that’s possible to achieve other ways but the OT’s implementation of it is really good and performance friendly, to the pint where if anything it’s become kind of overused but it’s still a really useful technique to have, it’s just easy to overdo it.
But yeah, the OT is really good for that kind of stuff, I can’t think of another piece of hardware I’ve used that does it nearly as well.