The SOUND VOLTEX pages on Giant Bomb have inconsistent capitalisation. The main capitalisation used by Konami themselves is SOUND VOLTEX (Example: Konami's rhythm game listing has different capitalisations for different series, with SDVX always in upper case) so that's what I'd advocate for.
Here's the changes requested:
Sound Voltex (Franchise) -> SOUND VOLTEX
No change for SDVX II, that's fine as is.
SDVX III コナステ isn't a direct port of the arcade version, with unique songs and new monetisation structures like a subscription so it should keep its own page with コナステ appended to it, I think. The website itself just calls it solely SOUND VOLTEX III in its FAQ but that might be confusing? It's up to the wiki mods' discretion.
In addition, could Sound Voltex IV: Heavenly Haven get a cover image? Either the poster or raw logo I uploaded would work.