I think (meaning I did no googling) that Honda didn't have a need to develop VTEC in F1 because A) VTEC is meaningless in a straight purpose race car (that's why VTEC-Killer cams exist), B) I'm not sure the rules would have allowed multi-lobe cams.
VTEC has no application in a race car. VTEC's big claim to fame is that a
STREET car could have the best of both worlds: low-rpm verifiability while meeting emissions and getting great MPG's while also having a racing oriented aggressive cam profile for higher RPM's allowing the engine to make power in an RPM range higher than the smaller cam profile would allow. It was like having a street engine and a race engine in 1.
On a race track, you only need the race engine.
