I will vote for it. However, It is a minor inconsistency and not particularly important to me as I very rarely have the need to close the left or right panel independently in Customize. In PhotoLibrary it makes more sense so the right panel can be closed independently. I never have the need to close the folder list. When on those very rare occasions I might want to close the left and right panels independently, in Customize, it is unlikely I would remember the key combination anyway and happily use my mouse for that purpose. However, I agree that it is an inconsistency that should be eliminated.
The reason I do so is to provide more screen “real estate” for my image preview … as I mostly work using the RHS palette (or, is it panel?) … with the LHS being mainly informational.
Yes. This is why I questioned somewhere else the decision to make the idea of “workspace” only related to the Customize mode. Why is the Workspace menu only available in Customize mode ? This is another strange decision. We should be able to specify the workspace in Library and Customize mode independently, especially when using a dual monitor configuration (but not only).