It's an inline 4-cyl motor with no balancer shaft so some vibes are inevitable.
The engine mounts go some way to isolating them from the chassis but won't completely eradicate them.
I've found that a full tank of fuel acts as damper, too.
Altering the TPS setting can move the most noticeable vibes up/down the rpm range by 500 - 1000 rpm.
Having worked on over 500 Gen 1s, I've found some that are definitely rougher-running than others. Some sound & feel the same even after the most careful carb synch.
Others - a small percentage overall - are what I call 'accidentally blue-printed' from the factory - all the rotating/moving mass components (pistons, rods, crank etc) are perfectly matched. These motors run like silk compared with the usual run-of-the-mill donks.
One of the FZ1OA guys, Ravenrider, blueprinted a Gen 1 motor during a rebuild and found that the difference in weight between lightest and heaviest piston was the equivalent of an old penny. That's quite a lot of imbalanced weight thrashing around at 5k rpm.
Some days mine runs smoother than others ... weather plays a part, I'm sure.
You could drive yourself nuts trying to eliminate vibes. Good luck with your efforts but don't be too disappointed if you don't achieve your holy grail.