I am not sure if it's a bug or a feature request, so let's start solid:
At this time, I have a solid parent node, and a dashed child node. Pressing "Inherit" on the child does not work.
Further, I "feel" that the "inherit" is not used efficiently here: I think inherit should be a drop-down option (not an action), and that that *everything* should inherit the root node (so, changing one-off all borders is trivial), and root node needs to be set to something (or, inherit global aka e.g. dotted).
Then, if someone wants to explicitly set a node, can do so (as it is now done).