I’ve been trying to understand whether bus lines actually do anything. The wires that go to and from a bus have to have net labels, to show which links to which. The manual says that the bus entry lines are only cosmetic. But if they’re omitted KiCad has no way to know which bus line a wire is associated with. Finally, leaving both entries and bus lines out still works because wires with the same net label are considered connected together.
Its true. But if your schematic has too many such hanging wires, it may be difficult for someone else to trace the nets & read the schematic easily. Blue bus line provides better visual info as to how the signal flow is.
Also I’ll prefer a single hierarchical label in multi-sheet schematic named D[0…7] instead of having individual hierarchical labels for D0 to D7
As for the subsheet scenario, I am quite unable to get this to work, even for the most trivial example. Unfortuately, as a new user, I cannot upload my test case.