you will most likely see blush as a haze on the surface of the resin. I always sand between coats…(including after the sealer coat) for two reasons: better mechanical bond, and elimination of blush, if it’s there. I do that with gloves on so I leave no oils that WILL give you bonding issues. Then I do a quick denatured alcohol wipe to pick up any oils, blush, dust, etc.
Make it part of the normal process and it will become a habit you won’t notice or mind doing.
BTW…high humidity will give you blush/bonding/curing issues, too.