Our local manufacturers and chicanes make copies of everything but if you buy from a trusted dealer chances of fake parts are low I agree that forward assist is rarely used but don't suggest the use of Chinese parts like firing pin and gastube.
Never tried Russian mags i have 6 surplus US mags with my A4 and one 30 round magpul p mag which works fine. if you can find a original magpul mag that would be good,beware of Chinese copies