It turns out emitted `render` events from Rails overlap cumulatively if you render a partial in a partial, and there's no nice way to differentiate parent partials from children, so the duration and allocations counts can be way off when the totals from the events are summed. View time can end up being twice as much as the total time, which is obviously impossible. Rails cheats a bit for it's rendering totals by taking the whole page template, but that doesn't work for SR, so allocations and rendering time have to be calculated a bit differently.