Didn’t know HSBC add-on cards also get their own free lounge access. Add-on cards are free too, and we can get up to 3 extra cards.
So technically each person can use lounge separately instead of sharing one quota. Pretty useful if you use lounge with family.
Also if you hold the rupay variant of the card, this card can be used to generate online lounge access thereby bypassing the card holder name checking. So primary user gets 2*4=8 lounge access per quarter, that's 32 visit per year 😋