I have a decent aluminum jack, probably similar to the Costco version you reference. It too doesn't have enough lift for my mid-size SUV, but plenty for the Cayman. For the SUV I put the jack on a couple of decent sized pieces of 2" pressurized & treated lumber,....instant 4" extra lift. Probably not OSHA certified, but if you use relative care and caution you won't have a problem.

As always, I immediately put jack stands underneath and lower the car onto them,....I never go under or work on the car with just a jack as support.