inheritance chain argument (default values) passing problem

Maybe it's not a bug at all, but i find argument passing/inheriting in the inheritance chain to be obscure.
Example:

## base.mako
<%page args="x='title',y='description'" />
<base>
	arg 'x': ${x}, arg 'y': ${y}
	<%block name="foo" />
</base>

## inheriting.mako
<%inherit file="base.mako" />
<%block name="foo">
	<title>${x}</title>
	<desc>${y}</desc>
</%block>

And two cases (first works, but second don't):

mylookup.get_template('inheriting.mako').render(x='title', y='description'))
mylookup.get_template('inheriting.mako').render())

Though args with default values are set in <%page> and are valid/visible in the inheritted template (base.mako; note inheriting (inheriting.mako<-base.mako) involved) , but not in the inheriting template and it's named blocks.
I know that i could pass args to named blocks via args param explicitly, but shouldn't <%page args (default values) also be inherited? (render() supplied args are visible in all templates/contexts)
In other wors: is there any posibility to set all arg default values in one place?

Start by reproducing the two cases with base.mako and inheriting.mako through mylookup.get_template('inheriting.mako').render(), comparing supplied arguments with the defaults declared in the <%page> directive. Trace how arguments reach the inherited template and its named block; done means the intended default-value behavior is established and covered by an appropriate regression test or documented as unsupported.