We had the bamboo. It didn't warp or cup. The eucalyptus is harder.

Floors don't warp at the drop of a hat. SOMETHING needs to happen TO THEM to get them to warp. The warp comes from exposure to MOISTURE. Moisture can be a leak (standing or visible water) or humidity (water vapour in the air).

Lack of HUMIDITY control (either in a localized area like a basement or as a whole-home concern) is the MOST LIKELY reason for floors to warp. That means you will need to assess your own home's situation. You need to be able to measure humidity/moisture in the air and in the substrate the floor will sit upon. Air humidity in the space the floor is being installed as well as humidity in the space below (crawlspace, basement, parking garage, etc). Or you must have the ability to test the SUBSTRATE (plywood, OSB, cement, gypcrete, etc).

Whew. As you can see, the exposure to moisture INSIDE THE HOME is 100% the homeowner's responsibility. No one else can or will do that for you. If you are concerned about a product "warping" then you must investigate the HOUSE before you worry about the product itself.

Good luck. Start with your HVAC system (start with the name/age/make) and call your local maintenance company to help you with the process. They will have the most amount of information regarding what you system can and cannot do as well as what can and cannot be ADDED to your system to get it ready for wood flooring.