Not F-35 - specific (of course), but a related data point:
Here at WRI, I had a long conversation last quarter with one of the check airman sim instructors about the subject of networked sims (our sims are in the midst of upgrading, to network with sims outside the building). Big Blue's intent is to network ALL sims together so every MDS can sim with/against each other as one big happy family, but when the sim folks ask questions like "How is the scheduling of all these networked sims going to work?", or "What happens when the sim instructor in one jet/crew position in the network needs to take a few minutes to "reset" a student - does everyone else have to sit there and wait, burning their valuable training time doing nothing?", Big Blue's answer is that they'll figure it out later. I asked those two questions myself, along with several other questions related to networked sim scheduling/ops, and every response was a shoulder shrug and "We don't know because they don't know, and they're in no hurry to figure out an answer." Our sim instructors know it will be a scheduling nightmare just with the C-17 sim across the parking lot, much less a sim 3-4 timezones away...
It's a cool idea, and I can see it being an awesome training tool for everyone involved, but I can also see it being one scheduling error away from being a total clusterfuck/waste of time for everyone involved.