So if you fork either of these matrix actions to 2 devices in the same PAN/WAN/Host, do you get 2 marks on the "master"? Risk aside, which can be mitigated if properly set up (not relevant to current question though). As far as I read, the marks flow to the master in the PAN/WAN section of core.... But no mention the other way.
I suppose you can read it either way:
You get a mark on 2 devices, both flow upwards, so YES!
Despite getting a mark on 2 devices, it was still one action (where you presumably didn't take the inherent penalty for going for multiple marks), so NO!
I'd lean towards "NO!" from a game balance point of view. It just feels like an exploit. (and I get that's totally what hacking is, but you're supposed to hack
in-game, you're not supposed to hack the rules!)