While it sucks that the quality of production cabs is poor, you are over thinking it. That rickety cab is easy to make rigid with well secured top or couple screws through back panel into wall.

Production cabs are not meant to be free standing, they need to be levelled, plumbed and secured to the wall.

Use a 30" base cab with butt doors(No stile between doors, better for storage) and single or double drawer at top. Interior dimensions will be 28 1/2 ? 22 3/4 and cab will be 34 1/2 tall. Level & plumb, secure to wall, add 25 1/2 ? 33 top, drill up/down through face frame at front to secure top and clips or cleat at rear for back. You can always add a cleat at back if needed.

I have used the set up above in many different industrial circumstances for machine/tool stands. It will easily carry 300lbs and be secure for years.

Putting 2-3 cabs together to make a bench creates more work/storage space and adds to rigidity.

If we can set those cabs to carry 1000# piece of stone, you can set up for shaky/wiggly 3D printer.

If you're unarmed, you are a victim.