LABEL request only allows one set, one add...

Is it an oversight that the LABEL request only allows one set, one add, or
one remove at a time (or one of each, but not two of any?)

For example, say I wanted to add <label-name>foo</label-name> and
<label-name>bar</label-name> to a version in one request.  The definition of
the LABEL request body is:

  <!ELEMENT label ANY>
  ANY value: A sequence of elements with at most one
  DAV:add, DAV:set, or DAV:remove element.

  <!ELEMENT add (label-name)>
  <!ELEMENT set (label-name)>
  <!ELEMENT remove (label-name)>

  <!ELEMENT label-name (#PCDATA)> PCDATA value: string

Since <add> can only contain one label-name, only one label can be added per
each request.  I would have to issue two LABEL requests to add both foo and
bar labels.

Lisa