Unless your instruction manual specifically states otherwise, you can shoot any slug or sabot you want through any of your three chokes.
The sabots will do no damage, the only real concern is that they may or may not stabilize and may keyhole on a target.
There's no real advantage to shooting a sabot through a smoothbore for most uses, especially if the gun only has a bead sight, but you can do it.
Sabots were designed for greater accuracy in rifled bores, but won't hurt a non-rifled barrel.
If it has chokes, it has no rifling.