I have been searching a few foreign sites for protectors, but the overall quality was film protectors (PET). I was looking to find glass or, at least, TPU.
I managed to find two options on Amazon that are somewhat decent:
This “custom fit” protector is close to something by Zagg (TPU), but will take about a month to arrive.
This is a glass protector made for the Canon 6D and has prime shipping.
Please note: An exact fit for the 6D is too large for the watch and many protectors are returned as too large for the 6D. I have tested multiple and this one fits almost exactly like those included with some watches. It was reported as too small for the 6D.
Hopefully this will save someone else the time or hassle) of finding one.
Thanks to mica for the idea to investigate Canon 6D protectors.