Dragging Node over Link doesn't fire mouseDragEnter

I have a problem with drag&drop Node over Link between Nodes inside and outside a Group.
Nodes 1-3 are placed inside Group, Nodes 4 and 5 - outside.

mouseDragEnter are called for Link12 and for Group when drag Node5 over Link12.
mouseDragEnter is called for Link34 but isn’t called for Group when drag Node5 over Link34.

How to teach DraggingTool to call mouseDragEnter for Group when Node5 is dragged over part of Link34 that placed inside Group?

That’s because Link34 is not a member of the Group. Only when all connections of a link are members of a group will the link also be a member of that group.

For example, if we pretended that Link34 were a member of Group, then what would we do if Node4 were a member of a second group? One could equally argue that Link34 would belong to the group that Node4 is a member of as well as the group that Node3 is a member of.