Having read this I thought it was very enlightening. I appreciate you finding the time and energy to put this information together. I once again find myself personally spending a significant amount of time both reading and posting comments. But so what, it was still worthwhile!
Just would like to share this python package "ur_rtde" designed to send and get data from UR robot via RTDE using python 3.
Documenation:
https://sdurobotics.gitlab.io/ur_rtde/index.html
Source code:
https://gitlab.com/sdurobotics/ur_rtde
It is well documented and there is a section dedication to the control of Robotiq gripper in the API.
The control of Robotiq gripper from outside is not simple but this package make it accessible.
The package is maintained by The University of Southern Denmark (https://www.sdu.dk/en/forskning/sdurobotics).