-disablegfxfirmware flag

Hello Everyone,

I have MB pro 13 (2017) and today I faced the following issue - OS X is only booting into safe mode, in normal mode it is trying to load but after some time just restarting. I turned on verbose mode to see what happens on boot and found that GFX firmware load process is trying to load something with 40+ attempts in loop but failing with something like "Failed to wake the ME".

I spent a lot of time in internet to figure out how to fix it and finally found only one solution which is just turning off gfx firmware load process using boot arguments. I executed the following line in terminal (recovery mode):
nmvar boot-args="-disablegfxfirmware"

So, right now I have the following questions: how does it affect my system? Did I turn off some feature? May this affect system performance? Why did I have to specify this flag? Why did this issue appear after update to High Sierra?