I would say that the issue is less than clear. I'm comfortable deferring to you in this matter as you've read
Data Trails and likely have a greater understanding of the underpinning logic.
I suppose the underlying question, which I'm not seeing an answer to, is whether Hosts live on grids or whether Hosts are basically grids unto themselves.
For discussion purposes, I was going off this passage from "Grids on a Run" on p. 233 of
SR5:
On a typical shadowrun, you’ll only be dealing with one or two grids, aside from the public one. Most likely, there will be the one you’re typically on (probably your local or public grid) and the one that your targets are on. It’s usually fairly obvious which grid your objectives are using. All the devices and people in a Shiawase facility will be using the Shiawase global grid, for example, while a thrill gang is probably on the public grid, and local law enforcement on the local grid.
To me, that was suggesting that the Shiawase facility - which one would
presume is a host, although this could be a case of the authors getting sloppy with their examples - was on a separate grid that you would need to hop to.
But then the very next paragraph says that the -2 penalty to interacting with something on another grid doesn't apply if you're inside a host, which undermines my logic because if a host is on a grid then why would there be a penalty on that grid
outside of the host but not
inside.
But, conversely, doesn't it seem strange that someone from the Aliied German States using their local host could be inside the Nukit Burger host with you in the PCC without having any sort of penalty for being on a different grid? That just presumes that every host - from Mr. Moran's home to the local Stuffer Shack - has a global presence that seems unlikely.
But, as I said, I might be using the wrong metaphors or not perfectly grasping the in-game logic. Go ahead and get your IC post up and don't worry about the grid-hop.