We thought we remembered something of that sort on the Deimos yeah, but none of us were sure. It probably does.
Anyway, slight alterations in geometry and stuff like hangar bays etc. aren't really major issues. The gamebreakers (used in a loose sense, obviously these aren't bugs that make the game not work) are turret and subsystem locations being changed from retail, as this changes mission balance - in some cases far more than one might think. Even in a 100% mediaVPs game balance would actually be off from what has been tested and validated, though admittedly not as much as in a mixed mediaVPs/retail game.
Well, it probably just needs to verify that the exact same files (not just tables, but assets too) were loaded on the client as the host. Perhaps allow a host override to enable or disable this behavior, whichever would make the most sense.
The absolute ideal solution from the multi community's point of view would be some system to simply not allow people with a corrupt installation to log onto FS2NetD in the first place (ideally pointing them towards IRC or the support forum for help), coupled with some kind of automated 'cleanup' function they could run to get rid of nonstandard crap plus the ability for FSO to automatically download the 1.20 patch from somewhere (even without using the installer) instead of people having to patch manually.
What I'm thinking here is that if somehow the game was aware of which files were
supposed to go into the fs2 root directory, and you ran the launcher with an added -cleanup command line argument, it would sort through the folder (and ideally /data/ as well) and move everything that looked wrong to a 'cleanup' folder where people could look through it later. Between this and a self-patching ability that would probably reduce time spent on multiplayer tech support by 90%. Easy. Probably many other kinds of tech support too for that matter. Of course such awareness would need to be able to work with TCs and the like which use completely different setups from fs2, so not sure exactly how it might be done. Hardcoding it would definitely be out.
However, ideally, the ability to block users of certain mods (in this case, mediaVPs) from joining games at the hosts discretion should not be necessary. Multi players like added eyecandy as much as everyone else does, and the FSU work is simply gorgeous. Plus if we're going to interest modern-day gamers in it, we pretty much need it to look as good as it can. So if at all possible, I'd rather see the models in question tweaked to align turrets and subsystems with their retail locations (other geometry differences are not a major issue, as mentioned before), as that would allow them to be used at the player's discretion depending on whether their system has the horsepower for it or not.