Multimod command line argument for the resque!
First and foremost - Derelict is not a FSPort campaign, it's a FS2(_Open) campaign and wouldn't benefit much at all from using FSPort data (which you have demonstrated by showing that putting FSPort VP's into Derelict folder seems to have no effect). In fact, puting the FSPort vp's into Derelict folder is a horrible idea because then you have conflicting ships.tbl and others, and you will most likely hit more or less serious problems some time during the campaign (it would kinda depend on the loading order of the VP's, though. D comes before F, so it's likely that all tbl files in derelict.vp would be used... but I'm not sure).
What you actually want to do is to activate both Derelict (or whichever mod you are playing with) AND the mediaVP's in order to get the new effects into the game playing Derelict (or other FS2 mods).
To do this, there's two ways: mod.ini files (which I personally find more of a nuisance to me because they assume that everyone names their MediaVP directory exactly the same) and using the custom command line window in the Launcher's Features tab.
Just add command line argument
-mod Derelict,mediavps to the end of the custom command line options. This will activate Derelict and mediavps, assuming your mediaVP directory is called "mediavps".
I personally use rather long-winded mod command line options because I like to keep the mediaVP directory as clean as possible (for troubleshooting reasons*), so any modifications between mediaVP releases I usually put in their own separate mod folders. Thus my current mod command line looks like this:
-mod FS2_Lightspeed,replace_retail_stars,mediavps,normalmaps,BobBeams,DDS_Beamglows,a_subspace,STARFIELD_REPLACEMENT-
FS2_Lightspeed adds LightSpeed's nebulae to the data usable by the game, and enables them in FS2 retail campaign.
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replace_retail_stars replaces the retail stars (suns) with new versions.
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mediavps is the mediavp directory I'm currently using.
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normalmaps contains a limited normal map pack for some models.
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BobBeams enables Bobboau's beam effects.
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DDS_Beamglows replaces the huge ANI beamglows with more memory-sensitive versions.
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a_subspace replaces the subspace effect with Axem's subspace vortices.
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STARFIELD_REPLACEMENT replaces the starfield skybox with my own.
If I were to play some of the major mods, I would add the name of that mod folder to the front of that long long line of mod folders.
Like, say, if I wanted to play FSPort, I'd use
-mod FSPort,FS2_Lightspeed,replace_retail_stars,mediavps,(...) etc. Same with Derelict, Blue Planet or anything. If I wanted to play Cardinal Spear, I would need to use
-mod Cardinal_Spear,FSPort,FS2_Lightspeed,(...) etc.
Mod folders really can't keep up with me, and I can't bother to go and edit them to have correct command lines just so that I could use the mod selection feature of the Launcher. I'm paradoxally lazy that way...
If you want to stick with mod.ini files, then you need to check exactly what it says in the mod.ini file in the mod folder you want to have the new models, effects and stuff with. The secondary mods section will need to have your mediaVP directory's name exactly as it is in your installation (quite obviously).
*keeping the mediavp directory as clean as possible is sensible for the same reasons you shouldn't put anything extra to root data folder.
root data folder is more important, because the contents in there are
always used, no matter the mod command lines, but quite similarly most people want to keep mediaVP's activated for the most of time they play (as you have demonstrated with this topic) and they have been usually pretty thoroughly playtested for issues and problems with them, so they should always be backwards-compatible with at least Retail FS2 campaign (and usually with all other previous missions as well, but that's neither here or there). New additions between mediaVP releases might cause problems and when you've tons of them stuffed into mediaVP folders, you won't know which of them it is that causes problems and you end up trying to remove them one by one from mediaVP's to test which is the problem. Or, you might simply not want to use some addition for some reason any more.
Putting new individual stuff in their own mod folders is a good way to keep potential troubleshooting much easier, if you're willing to have the little trouble with long mod command lines (which I personally find to be rather easy compared to gargantuan mess with mediaVP folder, which I have also tried at one point).
