Ok, I found something interresting while going through the Foundation thanks to some prodding by Jimmy.
It would appear that ships are registered on a Foundation level by their abrevation, so your ship shouldn't have been overwritten (it doesn't, at the Foundation level).
But it is overwritten on a race menu level, since those are registered through their (long) name. Which is the same.
So, putting a space after the long name "should" fix your problem (aside from the missing variable).
Also, about the bsod, not every scripting error generates a bsod, it might just let Foundation skip the plugin, also causing it not to show up, or generate a "silent" error (one that is visible in the console, but doesn't cause a bsod).
I'm thinking of releasing a SubMenu 3.7a, maybe also with TGL support, or something like that.