Suggested resolution [SUPERSEDED]:

Add a new paragraph after 9.8.1 [dcl.enum] paragraph 8:

For an enumeration whose underlying type is fixed, ...

An enumeration has the same size, value representation, and alignment requirements (6.7.3 [basic.align]) as its underlying type. Furthermore, each value of an enumeration has the same representation as the same value of the underlying type.

Two enumeration types are layout-compatible enumerations if ...