Not only can you twist the frame, you can damage the leveling jacks to the point they wont go back up.
Lessons learned from my first camper; put stick on levels on both sides of a corner of your trailer (when you are sure it is already level).
Amazon.com: Hopkins 08525 Graduated Level: Automotive
When you pull on to the campsite, get out and check the side to side level. If it's off, back up 2 or 3 feet and stack up some Lynx levelers where your tire was.
Amazon.com: Tri-Lynx 00015 Lynx Levelers, (Pack of 10): Automotive
Then drive onto them and check the side to side level again. Repeat till level. When that is good, put in wheel chocks (failure of this step can lead to amusement of other campers), unhook, and use your tongue jack to level front to back.
Only then put down your stabilizer jacks. Put all four down till they touch the ground. Then go around again giving each a half turn. Check that your door(s) are happy with this - then have the DW hand you a cold one for a job well done. :-)