Originally Posted by Hyacinthe

Follow-up and data point: Referred spouse from Business Plat to Personal Gold (her 2nd) just before the FYF was discontinued, using the URL trick. Her application was initially pending, approved a couple days later without contacting Amex (note she had cancelled her first Gold just a month before reapplying). Authorized user added during application and we entered her SPG card as existing account.
Got 25,000 referral within days of her approval. Gold received by FedEx. I was pleased to notice a new MR account was created. We just crossed $1,500 in spending, and 25,000 points posted with the transaction, like clockwork.
Needless to say that considering the circumstances, I am ecstatic of the outcome. I won't even chase the missing 5,000 for the authorized user. They may post automatically but if they don't, it's OK — no need to risk them looking into it... 50,000 MR for free in one credit check for a repeat applicant is more than worth it.