I’m just copying here part of a thread I had with Support. As requested, they said to include in Product Feedback…
As Workload is something that applies to people and not projects, it makes much more sense to be able to view workload per organisation/department/team/assignee.
Portfolios don’t necessarily contain the same subsets, since you manually add projects and thus project teams. Resources (assignees) may also be included in projects that’s are outside a portfolio and so not all their workload is seen.
While I think the Workload functionality is a great new addition to Asana, I believe this is just a starting point and vital to make it a lot more valuable, the developers really need to consider implementing these other views.