Today is more than very vast growing market with low-end android devices (specifically, tablets), especially for "third world countries". So, need for this is huge.
Devices are contrary to beleif, with quite satisfied quality for average usage (internet and office tasks), but not for gaming. Problem is OS. Chinese factories works with developers with some quite unusual approach.
OS is usually "fixed" with the scripts by using busybox. Devices are without boot.img and recovery.img (like "normal" devices). Developers everything set via scripts in main system. Devices are with mainly very wiered access to recovery and mostly with badly set permission (mostly end in boot loop).
Missing tutorials are:
01) What exactly was done, how, where, WHY (etc) developers using this "scripting approach", instead to classic boot and recovery images? It is very important as devices very easy enters in boot loop, without solution to exit (as recovery is regards scripting not accessible and debugging mode is also not accessible as device didnt entered in the level to activate it and it is not recognized by flashing tools.
02) Is it the way (how) to "fix" that solutions with some classic option (CWM, etc).
03) What and how to check and fix permissions in dumped ROMs.
04) Some other useful advices regards this devices OSs.