I think there's another way to look at it - from the majority side of things.
Do non-LPG OOFers object to the number of LPG threads? If it starts cluttering up the board too much, then its time to look at running a seperate one.
You could almost run the same rules on a HBV...but at least LPG is a big enough word to be searchable (unlike TC - too few letters).
Best it stays in one place - whether its in the General Help (most obvious place - although some threads pop up in General Chat) or its own forum.
I think it should be treated not by its specific nature, but rather by the thread count..if it was taking up 30% of threads in a section, then it needs its own TBH.
Personally, make no odds to me (although i'm in LPG transition mode, so could be biased), but am a mod on another forum and it annoys me when a new section is created (by request!) then gets no posts at all! OK, thats not going to happen with an LPG section...
For now, if "LPG" is put at the front of the thread title, then its hardly difficult to miss..