Setup is not a formality

More long-term problems with manufactured homes trace back to setup than to the home itself. A well-built home set badly will develop door and window alignment problems, floor issues and roof leaks. A modest home set properly will not.

The crew doing the setup matters as much as the factory that built it, and it is a fair question to ask a dealer who does theirs.

What the work covers

Foundation or pier system. Built to the manufacturer's spec and the local code, which are not always the same document.
Joining multi-section homes. Marriage line sealed, roof closed, interior finished where the sections meet.
Anchoring and tie-downs. Requirements vary by wind zone and are not optional.
Utility connections. Water, sewer or septic, power, and gas where relevant.
Skirting and final grading so water runs away from the home rather than under it.

Inspections and the walkthrough

Local inspection requirements vary, and a dealer should know exactly what your jurisdiction expects. Do a proper final walkthrough before you sign anything off: doors and windows operating cleanly, floors level, no gaps along the marriage line, and every utility actually tested rather than assumed.

Write down anything that is not right before you take handover. It is a much shorter conversation then than it is three months later.