Welcome! We have a 2014 Flagstaff 832IKBS, and have also noticed more movement than with other trailers we've owned. Part of the reason, I believe, is due to the use of torsion bar axles on the unit, and the axles being set closer together.
We also X-chock both sides of the trailer, and due to axle placement, the devices have to be nearly collapsed in order to fit them in. We also have a BAL device that is made to accomplish the same results, but rests on the ground. While it worked on the other trailers we've owned, it cannot 'shorten' enough to fit between the wheels on this model.
Currently, we also use the collapsible aluminum stabilizers that tension with a ratcheting strap. They are very light in weight and take very little space, but really seem to help. I place one under the step mount, and one at the front of the frame. We only use these when we're staying a week or two at one location, as the trailer movement isn't that distracting to us.
It sounds like your tech guy did an excellent job of explaining the trailer, and your experience operating it on your own was 100% normal. Be sure to share your ideas and adventures with us!
2016 Coachman Leprechaun, 319DS, Motorhome, Dodge Durango Toad