When I was buying direct from China forever ago it meant the Gold was bulk dipped onto the parts cand Upgrade gold resulted from a form of branches where the parts were separated and also called branch gold. The descriptions and methods were shown in pics,locations etc later by a dealer friend of mine who visited China and his suppliers. In your case now Beaufort may give you their experiences and recomendations. eg are there different warranties or credits buying upgraded kits or the need to upgrade,on which kits it applies and why.The shock for most people at the time was the contracting out by wholesalers in the industry in the peoples republic of China or Taiwan.
Kind regards Peter.