So I just did a quick test that I believe can help with answering question 2.
This specifically was tested using the same brick and cable I used when I posted this:
Utilizing the same brick and cable did not give me the same “Super Charge” when I plugged that into the Lume Stand and then put the tablet on the Lume Stand. I was about 92% power and it just showed Charging and did not show it Super Charging fast and incrementally with a decibel like 92.4%.
But as soon as I took the tablet off the Lume Stand and plugged the USB-C cable directly into the USB-C port it started Super Charging and showing the decibel. The Gif I created in that post is real time and not sped up or slowed down.
Reading the description of the Lume Stand does talk about a 33w brick so I am going to do a test with a brick that is closer specs to what you have with the Red Hydrogen one and the Anker 65w I have. I need to test with the Lume Stand with the tablet powered off and from the same battery percentage for an accurate test. (Gives me an excuse to watch some 3d movies this weekend.)
I think a quality brick like I am using and the Lume Stand both feature Over Charge Protection. But even with protection the tips outlined in my post still apply. Hope this helps.