Lock the frame before the price
Ask each supplier to name the primary frame, the secondary framing, and whether the proposal uses built-up plate, hot-rolled or cold-formed members. A clear span and a multi-bay layout do not share the same column line, so a single square-foot figure hides that difference.
Bay spacing, eave height and the design live load belong in the same note. If those values are still open, mark them open instead of letting a catalog span stand in for the site.