I get it. I always found a dishwasher too expensive for what I’d gain from it. Doing dishes manually for one or two adults who are diligent about reuse isn’t that much effort. But after being gifted a second hand one in excellent condition, I am very happy to have it in my home. The running cost is very reasonable. I’m unsure if I would replace it if broken. But for now it is serving me very well.

If I have understood it correctly then A should only get content from B because they are directly linked. Content from C will display on B (via ‘all’) but will not be sent over from C. Else A would never be able to block C.