[Upgrading, Modifying and Unlocking] xda-mark-d:
I hope this is the best place to ask this question since it's largely concerned with "upgrading".

Earlier this year I'd had enough of my Apple iPhone and its endless buggy updates which the phone would railroad you into installing and had no way to disable that. I elected to go for an Android phone. After spending a while looking I went for a Samsung Galaxy S8 which came with Android 7 and was literally flawless, the first such phone I'd had since iOS 8.6. Hurrah :)

However the phone has a major fault confirmed by the manufacturer. One key thing I checked was that I wouldn't be in the same position as with Apple, forced into installing updates. I am actually a software developer and one with a very limited tolerance of buggy things. I also understood that with Android you can't undo updates without invalidating the warranty. I have no problem with being informed they're available. Once. I can then review whether I want to risk it or not. I don't want to risk Oreo since there are plenty of reports of reduced battery life among other things and it brings nothing new of any significance and once it's on there it can't be taken off again.

So I checked the features and menus on the S8 before I bought it and went ahead.

This phone was great for about 3 months until the Oreo update was released. At which point the device began nagging. There are various settings which should, among other things, stop it downloading updates automatically and a developer mode option that should stop it updating. However as confirmed by Samsung these options simply do not work, it is a defect out-of-the-box and they are ignored. The phone will do what it wants not what you want.

So I'm now back where I was with Apple albeit the device is otherwise bug-free and superb. I have an uncancellable dialog box coming up repeatedly trying to railroad me into installing the Oreo update it should not have downloaded anyway. This is destroying what was a superb device. I've expended ages resetting it already. There aren't enough hours in the day. Android 7 is great. It isn't my primary device, that being my PC. I just want something that runs a few apps and checks email and that's about all. I don't want a "Samsung Experience" ;)

Samsung refuse to fix this, but as they've confirmed it's a fault I can get a refund from the retailer now. However I still need a phone. My question is:

Is it absolutely necessary to invalidate the warranty on a brand new phone out-of-the-box to stop this behaviour since they're all like it? (e.g. "rooting" is the only option)

Or, does anyone know more than Samsung do about their phones and can advise how the phone can be repaired by me (have done factory reset, denied internet, set not to update etc., as Samsung confirm, this part is broken and doesn't work). I could for instance block Samsung's IPs if I knew what they were but that will only work on WiFi here, not on mobile data. As I understand it the package that needs disabling is called "Software Update" but that isn't possible (again without invalidating the warranty which I'd rather not do since it's almost new).

I know how to scupper Microsoft's Windows Updates but that's because that's what I work with and I know the OS quite well and what they're up to. But I don't know how the Android OS works nor should I need to, really. Another reason for my reluctance to forcibly replace the OS.

Don't mind a pop-up box informing me updates are available with a button "Do Not Install" coming up when the update is released. What I don't want is what this phone and Apple phones do which is to suggest they know better than you do and eventually force you into installing them.

Or, which Android phones behave properly and don't have this sort of fault? That respect the user's settings and do not do whatever they like? I'll need to choose a new one anyway so this would be really useful.

Thanks for reading all that :)