When you assemble the legs, and have the retractable caster assembly with the cam in the caster up position, you are saying with the casters fully inserted into the housing, the holes to mount the brackets still leave the caster slightly proud, which would lift the machine off the floor in the up position?
Measure the length of the hole depth in the housing that should allow bottoming out and the caster stem. If the depth is insufficient, call Shopsmith Customer Service and get their advice. The stems on the casters might be too long, or the hole too shallow. The legs are stamped when made, delivered to Shopsmith, then drilled in a fixture they have been using for decades.
I suspect they will be able to direct you further and perhaps send out new parts if they identify the variance.
It is a new machine, and their supplier for the caster may be making it just a bit longer than before.
I know that in other threads we have discussed that the casters may not bottom out in the hole, and this may have increased again if the caster vendor varied an in the stem length.
They need to look into that. I would not be drilling more holes on a brand new set of legs without talking with them first.
Don't email them, call them.