`Can only use 'template' inside of a request handler` is thrown in middleware

[Altai-man]

My code is:

template-location 'templates';

route {
        after {
            template '404.crotmp', hash if .status == 404;
            template '500.crotmp', hash if .status == 500;
        }
...

and accessing it results in:

Can only use 'template' inside of a request handler
  in sub router-plugin-get-configs at /opt/rakudo-pkg/share/perl6/site/sources/BB802F84B227D34EB41F3FA87E22BD753F6E4033 (Cro::HTTP::Router) line 1373

which sounds a bit too restrictive maybe?