Altering array(composite-types) without breaking code when inserting them

I have:

create type thetype(width integer, height integer);create table
mytable(thetype thetype[]);

How can I make an insert statement, so if I add fields to the composite
type in the future, the code/query doesn't break?

Maybe by specifying the fields of the composite type in the query?

This can be done for normal inserts (non arrays):

CREATE TABLE mytable (t thetype);
INSERT INTO mytable(t.width, t.height) VALUES (11,22);

(so when I add columns to the composite later, my old sql-insert doesn't
break (not specified columns are inserted as NULL)).

PS: I always query this data together. The other way is to use json but
like this i have more flexibility (update an element of an composite type
in an array, more data-types) and less storage (no keys saved for each row
like in json/mongodb/hstore).