[Samsung Galaxy Note 9 Questions & Answers] IT_Architect:
Exactly! There are a lot of people that all they care about is cool, smooth, and game performance. For us, it is about automation of business and life tasks. When we've had an automatic note-taker via our call recording, it makes us furious when they sabotage it. Their idea of progress has been like going from air travel to cars to buses to walking. Next it will be confined to bed to keep you safe and from breaking some law.

The way you can determine if you can flash back to Oreo is by the boot loader revision level. If it is any 1.x version, you can. If it is a 2.x version you cannot. The way you are going to determine that is go into settings/about/software info, and look at Baseband version digit that is 5th from the right. Notice mine is a 1: N960USQS1CSD1. However, after you flash to Oreo, you have to do something to keep it there, otherwise tomorrow morning you will wake up to Pie. Provided it works even against Verizon, this is the safest, most understandable, and most maintainable way of doing that: https://www.youtube.com/watch?v=iyzsZXQ4zGA

Don't overestimate me. Have I done this a lot? Yes. Have I done it with the new phones and Note 9? No. I'm currently torn up with mine when flashing to a different provider. I'll let you know how that works out.

For backups you will hear about SmartSwitch. From what I see, that's not all you need because it restores everything. On our Note 3s, other than TWRP which requires root and works like a Windows image restore to a new hard drive, we use Helium. From what I've read it works on the Note 9 and Oreo as well, and does not require root. Helium enables you to select which apps you want to backup and select from the backup which you want to restore. MAKE SURE YOU CHECK THE BOX TO BACKUP APP AS WELL. Normally that box is unchecked because it assumes you want the latest version from the play store. You and I both know the play store lately has decided to rule your life via fiat and the new app is usually what sabotaged you. Next, go into the play store ON YOUR PHONE and turn off play store automatic updates. This is not completely trustworthy and sometimes they will reset it, but it will cut down on the number of sabotages. When sabotage happens, you can reset the update flag to turn automatic updates off again, and restore functionality using Helium, which means backup often.

The Note 4 is capable of LTE-A and thus not obsolete from the standpoint of today's networks. I like the 16:9 screen a lot better than the Note 9's 18.5:9 screen. The 9 is the same width as the Note 4, awkwardly high, and nobody has media for that screen ratio. Moreover, the Note 4 has a flat screen that you can protect, and a battery that lasts as long as the Note 9's, and it's replaceable. You can use SIMore cables and switch between 4 different SIMs and have them all fit behind the battery cover. You can use extended batteries on the Note 4 which is not possible for the Note 9. Moreover, the back of the Note 4 isn't glass to where you need to worry about that too now. Note 9 water proofing isn't that much of an advantage. They've been coated inside since the Note 3 and you can find YouTube videos with a Note 3 working full of water. They wash them out with distilled water and dry them afterwards. If a Note 9 leaks, it will never dry inside. I ran across a place that sells Note 4s a few weeks ago, I may want to find it back. They came with KitKat, which I can root without losing KNOX, and change to Lollipop or higher if I want to run Samsung Pay and lose root. If the Note 9 doesn't work out, I might get an N910A, and leave Verizon, because the Note 4 will go about anywhere in North and South America. For me, the only thing the Note 9 has going for it is it supports every band for every network in the Americas, I can use Verizon with it in the US, and I can do it all from the same phone.

Here is some good news. Several states are drafting legislation to require user replaceable batteries, and requiring cell phone manufacturers to give access to schematics to repair phones, and disallow manufacturer's power to sue you when you fix their phones with parts not from them and normally they won't sell them to them anyway. (Usually 3rd parties buy their parts from the same manufacturers the cell phone manufacturers buy them from.). The Apple slowdown spawned the replaceable battery blow back. Apple's suit in Norway against 3rd parties repairing their phones is when the SHTF for that, and Norway made sure it stunk to high heaven worldwide.