Well, I would like to confirm this myself, just to remind those who are travelling on ThaiSmile, if you hold ROP GOLD/PLAT you are entitled to access the lounge BUT you do need to SHOW YOUR CARD!!! because in ThaiSmile system do not have ROP registration, hence the ROP data will not show on boarding pass AND registered on barcode/system.

For those who have other *A GOLD you DO NOT entitled to access Royal Silk lounge when travelling on ThaiSmile since it is not in *A.