More than a year ago, there was some discussion and a proposal around
adding placement pools so cloud foundry admins could better target how
applications were placed on runners:
https://docs.google.com/document/d/1GNjQwGBh0BvfAYpX0LTUYn6h4oLz7v4P9pNy0xHZtMw/edit#

Did this work gain traction? I've looked through the release notes as well
as MEGA and CF Diego's public trackers and don't see stories for this work
either done or planned, though it could also be that I'm just not finding
it.

My goal is to place canary apps in specifically Z1 or Z2, as well as place
some internally used apps that, for networking reasons, should be in one
zone or the other.

-Matt Cholick