It's really difficult for me to explain what I am seeing here.
I have EDDI Installed, but don't load the EDDI.vap at all. I use "Singularity.vap" (HCS Profile) in VA as the main profile, then use both "Sigma 3.7.1.vap" and "KICS 4.1.vap" as global profiles. I have also opened Singularity.vap before hand, and using the "Options" tab, listed both global profiles as "Use commands from other profiles" in that dialog box.
When I say "Request Docking", Astra from Singularity.vap seems to respond with keystrokes and does the right thing, but I have Astra disabled in the Customizer with the box for the voice unchecked. The only reason I run Singularity is for the Ships Cat and to get the bindings checked so I can use the "HCS X55" bindings it provides. I expect "Sigma" to say "This is X-BRYB requesting docking permission and to do the keystrokes", but because variables are not being passed to Singularity from Sigma 3.7.1, Astra responds with keystrokes and does the right thing. With Singularty loaded as the main profile, and Sigma loaded as Global, I say "Who is on Duty". Sigma replies "It's Me, David, who is in charge of not set", It's me, David, who is in charge of not set" and so on for the rest of the crew.
I have these assignments set in Sigma, and If I load Sigma as the main profile, it works, by saying "It's Me, David, as First Officer, It's Me, Hazel, as Science and so on.
So, it seems the parameters and paths are not being passed to the "Main Profile" from the "Global Profile".
In all of this, I expect Singularity and it's voice commands to be ignored, as I have Astra's voice disabled and I expect Sigma to respond to all voice commands (which includes the paths and variables in that script).
KICS 4.1 seems to work fine and as expected, as it is for Music, and when I say "Play something" the paths and variables used by this script seem to locate the proper music files, all in local directories.
I'm sure your quick test shows one variable being passed correctly, but when used with complex scripts from three different profiles, it may get confused.
Furthermore, what I do with VA may not be recommended or advised, but for the most part, it all works except for variables and paths included in the Sigma.vap, do not seem to be passed properly, or those voice commands would not report "not set" when indeed, they are, both by the text files used and the paths to each text file which includes the proper variable.