Having explained that I know of no workaround, I have now worked out a workaround for this specific component, which further demonstrates that the bug is as described above.
By recoding the component so that the variable to be returned has a known prefix (in this case “path_”, the Component Output node can be configured to return only flow variables with that prefix. As there is then no longer a requirement to configure the flow variables (on the “flow variables” tab) , the node no longer fails on the inactive branch, and so this component is now “branch safe”.
I have left the remainder of the component alone, even though there are now calls to other nodes/components that are obsolete. By doing this, it demonstrates that the problem is not related to any other “inner workings” of the failing component.
You can see the subtle difference between this and the previously posted workflow, because even though the same branch is inactive, it now correctly remains inactive on the outputs of the component and Transfer Files nodes (ringed in blue below)
Component Stays Active on Inactive Branch - WORKAROUND demo.knwf (715.2 KB)