ok so first the original and fake question, from the pics you have posted they look almost exactly the same with both having the same components, now there are two ic's, you read the numbers on them, they will be same too i guess, hence both are doing the same job, i don't know if they are original or fake.
now the diagram and functionality shows that this is an advancer plus lambda emulation, the first part advancing the timing to suit the cng fuel the second part fooling the cu that lambda/o2 is working fine, to get rid of check engine light.
when you switch to cng, the fuel is not being controlled by the ecu and the feedback of the air fuel ratio goes off the scale, the ecu senses problem and gives a check engine light.
the unit gives a signal to the ecu similar to that of a working o2/lambda so the ecu remains happy.
now the rest of the switches.
switch 2 and 3 sets what type of signal the ecu is expecting from the lambda.
switch 1 sets what type of air monitoring system is in your car, there are two ways to calculate how much air is entering your engine, mass air flow MAF/AFM, and manifold air pressure MAP, the signal from both are different and the amount of advance to be done depends upon how much air entering and how much throttle, so you can select from this switch that which type of signal the unit should look for
now switch number 4 sets what type of advance you want to be done, there are two listed in the pic, adjustable and standard , i guess standard advances by a default value and in adjustable mode you can adjust the amount from the regualting advance dial.
now all what i have said is just my interpretation to what is written in the pic you posted, hence i might be wrong over here and stand to be corrected.