For PROMICE, I use a 2017-2018 average of station GPS data. I added an updated position for THU-U2. An improvement would be to have the .kml add the position date to the description and how it was obtained. For GC-Net, I use a table from Koni. I added an updated position for PET ELA from 2016.
Accuracy of positions is very important to avoid arriving in the field at an old location. In no cases, do I transcribe positions by hand as that can cause expensive problems not finding stations because of bad coordinates.