SteveX

I think you should be able to improve this with some adjustment to the DC table.  If you post your .pcl I will show my proposed adjustments.

Can you attach your current map so I can take a look at your settings - usually an openloop setup with MGP on one axis works well.
If you run wastegate only and no ECU control is the boost control stable and repeatable?

In the latest g4+ software help file there is a table of the common temp sensor resistance curves.  You could compare yours at 3 points - say ice water, boiling water and room temp to see if it is close to any of our built-in calibrations.
1.68K @ 20 definitely sounds like a 017 type.

No, done it many times.  I suspect under some conditions they probably have a haze of fuel on them in the manifold so I dont think liquid will hurt them.  If you are worried you can put it in glad wrap or a latex glove finger etc.

I haver found correctly mapped VVTI can make a lot of difference.
Glad you got to the bottom of the issue.

Ok then they need to check they have it set to the correct AUX out, one side of the solenoid should have 14v and the other side should goto the Pin on the ECU that corresponds with the AUX output that is configured in the Link ECU. What ECU do you have ?
All the outputs are short circuit protected and very rarely fail (I have never seen a failure) so I would think this is definitely a configuration issue rather than a hardware issue, however you can always move the VVT to one of the other AUX (needs to be AUX1 - AUX4) out to check if the driver has failed.
BUT please get them to press F12 with the engine running and scroll to the right and select VVT and send you a picture of the screen so you can post it here.
 

A simple test anyone can do is with the engine stopped run an Aux out test on the valve and you will hear it click, if it does click then there is probably a mechanical issue with the engine; If it does not click then you have an ECU/Wiring issue.
A more in depth test is to press F12 with the engine running and look at the actual VVT Data, which should show actual angles if the settings are correct.