Why can't one order a merchandised I-line, 120/240V, mid point grounded, 3 phase, 4 wire panel?

Issue:
Order a merchandised I-line, 120/240V, mid point ground, 3 phase, 4 wire panel on the Selector

Product Line:
I-Line Panelboards sold and supported in North America

Environment:
Application

Cause:
Availability

Resolution:
The selectors apparently lead to factory assembled panels.
However, the instruction book with an RTI I-Line says this panel can be used on a high leg system, so it is acceptable for this use.

Released for: Schneider Electric Canada