This story about the authentication of your "proof" at master Fu's last workshop, sounds very similar to Kenneth Lin's attempt to fabricate his black flag/5 flag Wing Chun story. Lin convinced his Sifu Tio to authenticate HKB Black Flag WC and later admitted via Sergio's video the story was all false.
The funny thing about this soap opera of Ermei 12 Zheung, both Lin and you went to ask Sergio to promote you as a legit WC researcher. My question to you is why do you choose Sergio to sing your song and promote your fabricated history of YKWC as the mother and the origin of all Wing Chun? Most people consider Sergio as nothing more than an airhead that would take anybody's story to promote his internet channel to make money. Base on the past history, nothing legit, only fabrication of history, cherry picking stories from Sergio's channel. With that kind of reputation, you still want to choose Sergio as the promoter for your own story. You should either be ashamed of yourself for taking advantage of Sergio's inexperience in WC or for thinking the rest of us so gullible.