That's actually exactly what I was doing in the full context. I can see 16 calls over the lifetime of the request, but what was confusing me was how they could

That's actually exactly what I was doing in the full context. I can see 16 calls over the lifetime of the request, but what was confusing me was how they could have 16 nested calls forming some ob_start();ob_start();...ob_end_flush(); Maybe some crazy way to avoid having to return text up the tree through function returns. But I read the post again and it said nothing about nesting them, so it's probably just something like 16 sub-templates or whatever as you suggest being processed at different intervals, not necessarily nested, with the gc not collecting frequently enough.