[rickst29]

When the swing hitch is swung over, I think it's a good idea to avoid the torque (on the frame) which the unbalanced weight of the swing hitch itself. I crank the wheel down enough only to match the weight of the swing hitch itself, not to actually raise the trailer. At home I have the tires almost completely off the ground, and the trailer resting on the leveling lifts.

In camp, I take it completely off-- the trailer is held up by the levelers, and only a little bit by the tires, with no weight at all on the hitch. (Which I leave in the hooked up position, not swung around.) Away from the garage, I do leave the tires with some weight on them-- raised only to about 1/2 above their "fully loaded" riding height.

I think that you're creating "flat" spots in the tires if they're parked in one spot for a long time (with the full load of the trailer on the tires). So, if it's for longer than just one night, I raise the TM so that nearly all the weight is on the levelers, NOT the tires or the front hitch wheel.
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So I'm much closer to Service Guy's recommendation. But yeah, if the wheel isn't bearing weight, you can leave it on there-- as long as it isn't high enough off the ground to loose.