Do you have to seal holes on NEMA 3R enclosures with weatherproof blanks?

[jar546]

Here is an example where the installation of a new ATS changed the feed location from a NEMA 3R meter enclosure from bottom side to bottom. This left an open hole (seen in photo below) on the bottom right. The hole is located below the level of live parts just in-case that matters to you.

Would you require that this hole be sealed with a weatherproof blank? If so, what code section would you cite. If you think it is OK then please say so.

 

[ICE]

110.12(A) Unused Openings. Unused openings, other than those intended for the operation of equipment, those intended for mounting purposes, or those permitted as part of the design for listed equipment, shall be closed to afford protection substantially equivalent to the wall of the equipment. Where metallic plugs or plates are used with nonmetallic enclosures, they shall be recessed at least 6 mm (1⁄4 in.) from the outer surface of the enclosure.

The gauge of the metal used to make the plug is less than the metal used to make the cabinet. The plug is not water tight so the protection provided is less than the wall of the cabinet.