It's possible to go even lighter with the headset.
https://velobase.com/ViewComponent.a...ee49c&Enum=111
but the difference isn't enough to justify the added weight of any adapter I have found.
and sticking to threaded stems if you want a stiff front end you have to pick a pretty solid stem which comes with a weight penalty - Seems to me the differences in weight are negligible and the inni upgrade is hard to argue.
Or am I missing something?