Need some help/advise Yamaha 2002 F225 4 stroke

[JC Eckstein]

Been struggling for about 7 month getting my F225 fixed. Been through 3 Yamaha Certified Mechanics and almost $2K with no results whatsoever. Tried to get a hold of Yamaha direct but there seems to be no phone number because they want you to go to a dealer.
Here is the issue:
Engine shakes strongly at >3400RPM (acts like misfiring or safe mode)
It just started to have a mild vibration at lower RPMs as well
Some times problem goes away after re-start
Once the engine runs correctly (after re-start) it will run fine until it is turned off again
Engine trips no alarms even when various sensors are unplugged But if you pull the safety cord alarm goes off
Engine does not communicate with Mechanic’s lap-top

This is what we have done/checked so far:

There are no issues with the fuel, filters or pumps (pressure)
No issue with the timing
No issues with the starter harness
No corrosion on battery cables
No issues with the VST

[JC Eckstein]

Found problem

Although, we tested the Shift Position Switch by disconnecting it during test drive, it turned out that it was the problem. The faulty switch simply made the motor think that it is in Neutral, which has a factory limit of 4300RPM, when in fact it was in drive.

[rodbolt17]

wrong.
no factory spec on RPM limiting due to a faulty shift position switch.
its done by did the ECU see an in gear or out of gear signal and a crank signal.
then did it see a shift signal.

[rodbolt17]

and
its a switch.
simply on or off.
laptop displays it.
why did the tech not catch it?
lazy untrained techs.