@IKS
Thanks again for your feedback. You mentioned to me in another discussion about the camera and mic. The camera and mic are built into the Dell monitor I am using (Dell S2340T). From what I can tell, it is a combined isochronous RealTek (570a?) module. Per your advice, I downloaded several USB camera apps and did finally get it to work (sort of) but got many crashes and freezes in the process and had to give up.
I must assume the camera (and mic) issues were likewise due to the GPU memory since they all have a video feed of the intended photo and IF they are able show that video, they all freeze or crash at some point.
But, I get it. The RPi is what it is... at $30, it has provided a good bit of education already and even if I get the XU4 to work as I hope, I will still be using the RPi to learn more with and I will likely think of another project for it, possibly on the EmteriaOS. (constant display style "magic mirror"?) We'll see. Maybe another forum member here has a better suggestion.
My current goal is, as you say, to create a generic tablet for all kinds of activities cluttered with cpu-intensive apps... then mount it on my refrigerator as a "Family Hub" interactive kiosk. Mostly just for the time, weather and calendar but also for shopping lists, recipes, notes, and a little music to cook along with. Basically, I want the Samsung FamilyHub smart fridge but without the Samsung refrigerator and walled garden Samsung app store. I even had some hopes of running a voice assistant with the mic and utilizing the camera to photograph invites to add to the calendar. Mostly I like running big desktop widgets that can be seen at a glance which I am sure is not helping my cause on the RPi. But, I had to try RPi to see how far towards my goal I could push it and going forward I wonder if even the XU4 is going to be powerful enough. Without much of a comparable knowlege base for my build, I am just using the "guess and check" method filled in with as much forum reading as I can handle before confusion sets in.
To me, your development crew at Emteria is a bunch of wizards! From what I can tell, the product is great, only limited by the hardware. If there was an EmteriaOS build for the ODROID XU4, it would be my first choice and if I dream up another Pi project, it will again be my choice. You guys do really nice work.
However, I do have one request... I would love to see a part of the forum here where users can post their projects. Even "Industrial" type projects are interesting and a great way to see what really is possible to do with Android on the tiny Pi.