I just had my referral code AND discount deactivated for unknowingly abusing a rule. Shared it in an oculus quest VR group, even people I play with and it was deactivated without warning regardless of the fact that 70% of my referrals are friends and family.
So my advice is only share your code via private messaging to friends and family. I was frustrated by this because on the referral page it literally says "X NUMBER OF REFERRALS UNTIL FREE SHADOW!!" but nothing about rules of abuse.