Will this blister when applied to plexiglass or Lexan?

As long as the acrylic is not brand new and has been given some time to outgas, you will be fine to install this film. Add a little extra soap to the water as the glue will bond to acrylic quicker than glass. Also keep in mind that the adhesive may be an issue if you ever decide to remove this film off the plexi as it may leave some residue behind.