EXPLAIN doesn't explain operations on inheritance trees

If I create a class A and make subclasses A1 and A2, then
I get useful explanations when I say "EXPLAIN SELECT * FROM A1 ..."
but not if I ask about a query on the inheritance tree A*.

tgl=> EXPLAIN SELECT * FROM A* WHERE accountid = 3;
NOTICE:  QUERY PLAN:

Append  (cost=0.00 size=0 width=0)

EXPLAIN

With "explain verbose" it is possible to see that the APPEND plan
has substructure, but it's hard to see what's going on in that format.
How come plain "explain" doesn't show the subnodes of an APPEND plan?

            regards, tom lane