You can’t import grooves. Nor can you “live record” unquantized sequences. So you have to place new triggers perfectly on the grid. But like noxical says you can then use microtiming to shift triggers around manually afterwards, which is very easy and fast to do. You hold down the trigger you want to move and use the cursor keys to nudge that step in either direction.
The swing feature is also nice. You can mark which steps will be affected by the swing setting, so the swing doesn’t have to affect all even-numbered steps if you don’t want to (it does so by default, though).
Slightly off topic:
A developer here (Rusty) is close to releasing a very impressive and powerful PC editor for the Octatrack. Perhaps “Apply groove template to pattern” is an idea he’d like?