Can I update to the latest version of Android on a generic off-brand tablet? My question is related to this community wiki. I found an affordable white-label Android tablet for €99 a few days ago and I'm considering buying it. Its specs seem fairly decent for its price range, especially given that I'd prefer a 10-inch tablet. Unfortunately it's a very generic brand (IT WORKS), so I don't think that I'll get any OS updates.

Is it possible to install the latest version of Android on an off-brand tablet? I'm fine with vanilla Android or a popular custom ROM like Cyanogenmod. I'm asking specifically about off-brands because there's a big chance that the modding community doesn't have a ready-made solution for that specific tablet. The device comes with Superuser already installed, so I'm assuming that it is pre-rooted. I'm not familiar with the ROM flashing process and I've never done it before.
There's no special procedure that works with unbranded tablets. As the question you've already found describes, if there's no official upgrade from the manufacturer, you need to look for a custom ROM based on a newer Android version. Where can I find stock or custom ROMs for my Android device? gives you some places to look.

There's only one feature peculiar to unbranded tablets and phones. Often, several apparently different unbranded tablets or phones will contain exactly the same hardware, because they're based on the same "reference design". In this case, it may be possible to use a ROM for another unbranded device with the same hardware. It's quite hard for an end-user to know whether this is the case: it's not enough that the tablets are all based on the same SoC, but if all the spec-sheet specs are exactly the same, it might work. Flashing a wrong ROM can have bad side-effects, potentially bricking the device, so I wouldn't recommend trying this carelessly, but it may be that you can find a post on a forum such as XDA developers from someone who has already found a ROM that works on your device.