You are technically overriding the default template when you specify another template in the controller, which means the entire page will be rendered using the new template. I’m not sure iron router supports this feature at this moment.
@sato1 on this question. I’m confused on this same scenario, although I feel like there may be a different way of doing it without actually nesting layouts. If anyone’s still watching this thread, is there any advice on this?
Looks like nested layouts are a feature request in Iron Router. Also, looks like there’s already a package for nesting layouts (although the documentation is confusing me a bit) called Iron Layout