I live in Zone 4a on a concrete slab foundation.  I am re-insulating the wall between my unconditioned garage and conditioned living room.  I tore out all the old fiberglass and installed mineral wool.  Next I am going to install 1″ of foil-faced poly iso in a continuous layer, a furring strip for air barrier, then drywall.  My question is how to air seal the bottom plate/wall to the slab.  I was going to use Siga Fentrim because it seals to concrete, but which “layer” should I apply the tape to?

1. Framing/slab before I put polyiso on
2. Polysio/slab before I put furring strips on
3. Drywall/slab

It seems like option #2 would be the easiest and wouldn’t get damaged if the drywall got damaged?

Any opinion is helpful! Thanks.