As indicated, I am a long term, but relatively inexperienced member. While my experience here comes about as a result of several brickings, 8 reformats, and reading at least 200 pages of well-intentioned material from which I had to draw conclusions (a lot dead ends, reformats and bricks!), and against senior member Afaneh92's stern warning, I decided to proceed. God help me, but he did mention something about "encryption"! Lest I be accused of being "off-topic" or something equally bad, I am going to leave out the processes and events of the past 3 weeks, and state my results. I am an attorney and suffice it to say that a rooted android phone is best way to interact with systems used in this profession to avoid embarrassment or worse. I am on 13,and used the latest version of twrp. Aside from root, use the stock ROM.
First, I learned that the encryption problem is a possible show stopper. You guys can overcome it but each generation of devices seems to be increasingly difficult. The password - encryption thing was a rude awakening. Using every technique advised, I am not sure I succeeded even though I was finally able to move through the flashing and subsequent processes without seeing warnings or being stopped by encryption. This process, more than anything else, caused more brickings, looping and repeated collapsing of the device.
I still think there are encryption issues. When I finally got the tab stabilized and was able to interact with it, I again flashed the tar. I put Odin in a manual kind of way where it would not automatically reboot. The pressing button timing thing on the "rebound" is tricky.. at least, to me. Since the combination of of buttons was also inconsistent in the blogs, I had no way of really knowing whether the failure to flash was my clumsiness, the wrong buttons or the wrong tar. Putting Odin on manual, made it breeze.
Having believed that the recovery was now flashed and safe, I then loaded Magisks as Afaneh and the blogs suggested. While not apparent at first, neither root nor the recovery were stable. When I finally looked at what the recovery was reporting to me, that there was no data, no space for data, etc, yet the phone was clearly functional to a degree, I went back to the blogs.
The process of trying to identify and fix that, resulted in the total collapse of the device again.
After a few days, I decided to take a reverse approach. I learned how to patch the boot file from the stock ROM with Magisks. I also incorporated the patched img into the tar of the stock ROM itself, just in case. However, when I used the patched img, etc, Magisks flashed and worked like I am used to! I then flashed the twrp again. However, I had forgotten to format partitions and the tab did not have enough space to restore my backups. I wiped and reformatted twice. I flashed twrp effortlessly and the tab functioned and continues to function, in root reliably.
All my utilities for diagnosing issues are showing nothing out of place, except for root. Still, twrp cannot "see" the partitions or what is in them. It cannot mount what it does not recognize and, from experience, the process of trying to get it to see the partitions, etc, so that it can mount them, will lead (me) to another round angst.
To date, I have seen people of all levels ask questions (often, as I now know the response to which won't lead to the problem) or, the more senior members talk aound the problem. I have not seen it reified in a concrete way. I am following this thread religiously because I imagine any breakthroughs will be reported here.
For my purposes, to the extent it works, the recovery is OK. Again, root is working perfectly. One aspect of the recovery I really miss is the inability to back up. Over the years, I have come to rely on that. For those of us who don't have time reconstruct a device every time something happens, the twrp image back up has become almost indispensable.
So, the twrp works it just depends on one's needsm