Since we're on the subject of wheel chocks (not chalks), One thing that I've had to be aware of with having an auto-level system, is that, on occasion, I've had the low-side wheels off the ground, so chocking is useless on that side. Another thing is that when you chock prior to unhitching, then leveling, if you do have tire contact but it's somewhat "unloaded" due to leveling and you kick the chocks tight, you need to remember to pull them back in slightly or you'll either crush them (not happened yet) or you'll not be able to get them out without re-raising the rig up. Yes, I =have= had to do that.
Lyle