We have implemented the changes TIG described in his previous post.
I'd like to ask those who had problems with their plugins being installed to the wrong folders to restart their SketchUcation Tools Extension Store and check the Settings / Path tab to see if the faulty folders are now excluded from the list of possible install folders.
The Extension store on restart might throw an error about the default installation folder not existing. After the error message please go to the Settings / Path tab and make sure the correct installation folder is selected there.

Thank you for the information.