I had vibrations on one XS 650 because a left side crash disturbing the crank.
I used and still use a type of
Rubber foam grips ca 50 % larger diameter than stock and softer.
I would prefer smaller diameter I have small hands.
And had / have weights --- Dampers in bar end
Stock handlebar
With one size over on pilot jet and main jet Which is probably a bit to much
Crank is now adjusted ..
The word is Perfect ..,in the vibration sense .. especially at highway speeds.
Between 50 km / h and 100 km / h
Absolutely nothing
Nothing else is perfect on the bike but there are no vibrations anymore in the grips.
Absolutely Nothing felt in the hands. Anymore.
So I am reluctant to go down on jets.
I fitted Progrip 714 grips and love them. Put them on my DRZ too.